WorldWideScience

Sample records for radiation damage monitoring

  1. Radiation Damage Monitoring in the ATLAS Pixel Detector

    CERN Document Server

    Seidel, S

    2013-01-01

    We describe the implementation of radiation damage monitoring using measurement of leakage current in the ATLAS silicon pixel sensors. The dependence of the leakage current upon the integrated luminosity is presented. The measurement of the radiation damage corresponding to integrated luminosity 5.6 fb$^{-1}$ is presented along with a comparison to the theoretical model.

  2. Radiation damage monitoring in the ATLAS pixel detector

    International Nuclear Information System (INIS)

    Seidel, Sally

    2013-01-01

    We describe the implementation of radiation damage monitoring using measurement of leakage current in the ATLAS silicon pixel sensors. The dependence of the leakage current upon the integrated luminosity is presented. The measurement of the radiation damage corresponding to an integrated luminosity 5.6 fb −1 is presented along with a comparison to a model. -- Highlights: ► Radiation damage monitoring via silicon leakage current is implemented in the ATLAS (LHC) pixel detector. ► Leakage currents measured are consistent with the Hamburg/Dortmund model. ► This information can be used to validate the ATLAS simulation model.

  3. Monitoring the Radiation Damage of the ATLAS Pixel Detector

    CERN Document Server

    Cooke, M; The ATLAS collaboration

    2012-01-01

    The Pixel Detector is the innermost charged particle tracking component employed by the ATLAS experiment at the CERN Large Hadron Collider (LHC). The instantaneous luminosity delivered by the LHC, now routinely in excess of 5x10^{33} cm^{-2} s^{-1}, results in a rapidly increasing accumulated radiation dose to the detector. Methods based on the sensor depletion properties and leakage current are used to monitor the evolution of the radiation damage, and results from the 2011 run are presented.

  4. Monitoring the radiation damage of the ATLAS pixel detector

    International Nuclear Information System (INIS)

    Cooke, M.

    2013-01-01

    The pixel detector is the innermost charged particle tracking component employed by the ATLAS experiment at the CERN Large Hadron Collider (LHC). The instantaneous luminosity delivered by the LHC, now routinely in excess of 5×10 33 cm −2 s −1 , results in a rapidly increasing accumulated radiation dose to the detector. Methods based on the sensor depletion properties and leakage current are used to monitor the evolution of the radiation damage, and results from the 2011 run are presented

  5. Monitoring radiation damage in the ATLAS pixel detector

    CERN Document Server

    Schorlemmer, André Lukas; Quadt, Arnulf; Große-Knetter, Jörn; Rembser, Christoph; Di Girolamo, Beniamino

    2014-11-05

    Radiation hardness is one of the most important features of the ATLAS pixel detector in order to ensure a good performance and a long lifetime. Monitoring of radiation damage is crucial in order to assess and predict the expected performance of the detector. Key values for the assessment of radiation damage in silicon, such as the depletion voltage and depletion depth in the sensors, are measured on a regular basis during operations. This thesis summarises the monitoring program that is conducted in order to assess the impact of radiation damage and compares it to model predictions. In addition, the physics performance of the ATLAS detector highly depends on the amount of disabled modules in the ATLAS pixel detector. A worrying amount of module failures was observed during run I. Thus it was decided to recover repairable modules during the long shutdown (LS1) by extracting the pixel detector. The impact of the module repairs and module failures on the detector performance is analysed in this thesis.

  6. Monitoring radiation damage in the LHCb Silicon Tracker

    CERN Multimedia

    Graverini, Elena

    2018-01-01

    The purpose of LHCb is to search for indirect evidence of new physics in decays of heavy hadrons. The LHCb detector is a single-arm forward spectrometer with precise silicon-strip detectors in the regions with highest particle occupancies. The non-uniform exposure of the LHCb sensors makes it an ideal laboratory to study radiation damage effects in silicon detectors. The LHCb Silicon Tracker is composed of an upstream tracker, the TT, and of the inner part of the downstream tracker (IT). Dedicated scans are regularly taken, which allow a precise measurement of the charge collection efficiency (CCE) and the calibration of the operational voltages. The measured evolution of the effective depletion voltage $V_{depl}$ is shown, and compared with the Hamburg model prediction. The magnitudes of the sensor leakage current are also analysed and compared to their expected evolution according to phenomenological models. Our results prove that both the TT and the IT will withstand normal operation until the end of the L...

  7. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  8. Nonlinear Ultrasonic Techniques to Monitor Radiation Damage in RPV and Internal Components

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Laurence [Georgia Inst. of Technology, Atlanta, GA (United States); Kim, Jin-Yeon [Georgia Inst. of Technology, Atlanta, GA (United States); Qu, Jisnmin [Northwestern Univ., Evanston, IL (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wall, Joe [Electric Power Research Inst. (EPRI), Knoxville, TN (United States)

    2015-11-02

    The objective of this research is to demonstrate that nonlinear ultrasonics (NLU) can be used to directly and quantitatively measure the remaining life in radiation damaged reactor pressure vessel (RPV) and internal components. Specific damage types to be monitored are irradiation embrittlement and irradiation assisted stress corrosion cracking (IASCC). Our vision is to develop a technique that allows operators to assess damage by making a limited number of NLU measurements in strategically selected critical reactor components during regularly scheduled outages. This measured data can then be used to determine the current condition of these key components, from which remaining useful life can be predicted. Methods to unambiguously characterize radiation related damage in reactor internals and RPVs remain elusive. NLU technology has demonstrated great potential to be used as a material sensor – a sensor that can continuously monitor a material’s damage state. The physical effect being monitored by NLU is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave. The degree of nonlinearity is quantified with the acoustic nonlinearity parameter, β, which is an absolute, measurable material constant. Recent research has demonstrated that nonlinear ultrasound can be used to characterize material state and changes in microscale characteristics such as internal stress states, precipitate formation and dislocation densities. Radiation damage reduces the fracture toughness of RPV steels and internals, and can leave them susceptible to IASCC, which may in turn limit the lifetimes of some operating reactors. The ability to characterize radiation damage in the RPV and internals will enable nuclear operators to set operation time thresholds for vessels and prescribe and schedule replacement activities for core internals. Such a capability will allow a more clear definition of reactor safety margins. The research consists of three tasks: (1

  9. Nonlinear Ultrasonic Techniques to Monitor Radiation Damage in RPV and Internal Components

    International Nuclear Information System (INIS)

    Jacobs, Laurence; Kim, Jin-Yeon; Qu, Jisnmin; Ramuhalli, Pradeep; Wall, Joe

    2015-01-01

    The objective of this research is to demonstrate that nonlinear ultrasonics (NLU) can be used to directly and quantitatively measure the remaining life in radiation damaged reactor pressure vessel (RPV) and internal components. Specific damage types to be monitored are irradiation embrittlement and irradiation assisted stress corrosion cracking (IASCC). Our vision is to develop a technique that allows operators to assess damage by making a limited number of NLU measurements in strategically selected critical reactor components during regularly scheduled outages. This measured data can then be used to determine the current condition of these key components, from which remaining useful life can be predicted. Methods to unambiguously characterize radiation related damage in reactor internals and RPVs remain elusive. NLU technology has demonstrated great potential to be used as a material sensor - a sensor that can continuously monitor a material's damage state. The physical effect being monitored by NLU is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave. The degree of nonlinearity is quantified with the acoustic nonlinearity parameter, β, which is an absolute, measurable material constant. Recent research has demonstrated that nonlinear ultrasound can be used to characterize material state and changes in microscale characteristics such as internal stress states, precipitate formation and dislocation densities. Radiation damage reduces the fracture toughness of RPV steels and internals, and can leave them susceptible to IASCC, which may in turn limit the lifetimes of some operating reactors. The ability to characterize radiation damage in the RPV and internals will enable nuclear operators to set operation time thresholds for vessels and prescribe and schedule replacement activities for core internals. Such a capability will allow a more clear definition of reactor safety margins. The research consists of three tasks

  10. Prediction of UV spectra and UV-radiation damage in actual plasma etching processes using on-wafer monitoring technique

    International Nuclear Information System (INIS)

    Jinnai, Butsurin; Fukuda, Seiichi; Ohtake, Hiroto; Samukawa, Seiji

    2010-01-01

    UV radiation during plasma processing affects the surface of materials. Nevertheless, the interaction of UV photons with surface is not clearly understood because of the difficulty in monitoring photons during plasma processing. For this purpose, we have previously proposed an on-wafer monitoring technique for UV photons. For this study, using the combination of this on-wafer monitoring technique and a neural network, we established a relationship between the data obtained from the on-wafer monitoring technique and UV spectra. Also, we obtained absolute intensities of UV radiation by calibrating arbitrary units of UV intensity with a 126 nm excimer lamp. As a result, UV spectra and their absolute intensities could be predicted with the on-wafer monitoring. Furthermore, we developed a prediction system with the on-wafer monitoring technique to simulate UV-radiation damage in dielectric films during plasma etching. UV-induced damage in SiOC films was predicted in this study. Our prediction results of damage in SiOC films shows that UV spectra and their absolute intensities are the key cause of damage in SiOC films. In addition, UV-radiation damage in SiOC films strongly depends on the geometry of the etching structure. The on-wafer monitoring technique should be useful in understanding the interaction of UV radiation with surface and in optimizing plasma processing by controlling UV radiation.

  11. Radiation monitoring

    International Nuclear Information System (INIS)

    Larsson, L.Eh.; B'yuli, D.K.; Karmikel, Dzh.Kh.E.

    1985-01-01

    Recommendations on radiation monitoring of personnel, used medical ionizing radiation source, are given. The necessity to carry out radiation monitoring of situation at medical personnel's positions and personnel dosimetry is marked. It is convenient to subdivide radiation monitoring into 3 types: usual, surgical and special. Usual monitoring is connected with current work; surgical monitoring is carried out to receive information during a concrete operation; special monitoring is used to detect possible deviation from standard conditions of work or when suspecting them

  12. Radiation damage of nonmetallic solids

    International Nuclear Information System (INIS)

    Goland, A.N.

    1975-01-01

    A review of data and information on radiation damage in nonmetallic solids is presented. Discussions are included on defects in nonmetals, radiation damage processes in nonmetals, electronic damage processes, physical damage processes, atomic displacement, photochemical damage processes, and ion implantation

  13. Radiation damage to mushrooms

    International Nuclear Information System (INIS)

    Sattler, P.W.

    1986-01-01

    This document contains newspaper cuttings and correspondence with various ministries in Hessen on the subject of radiation damage to mushrooms from the Odenwald area. The reader is given, amongst other things, detailed information on radiation damage to different types of mushroom in 1986. (MG) [de

  14. Radiation monitor

    International Nuclear Information System (INIS)

    Pao, C.T.; Green, W.K.

    1978-01-01

    A system for indicating radiation from a radioactive fluid such as a gas wherein simultaneous indications of the activity concentration of radioactivity of the gas, the radiation dose rate and average energy of the radiation are provided

  15. Radiation damage of uranium

    International Nuclear Information System (INIS)

    Lazarevic, Dj.

    1966-11-01

    Study of radiation damage covered the following: Kinetics of electric resistance of uranium and uranium alloy with 1% of molybdenum dependent on the second phase and burnup rate; Study of gas precipitation and diffusion of bubbles by transmission electron microscopy; Numerical analysis of the influence of defects distribution and concentration on the rare gas precipitation in uranium; study of thermal sedimentation of uranium alloy with molybdenum; diffusion of rare gas in metal by gas chromatography method

  16. Radiation damage prediction system using damage function

    International Nuclear Information System (INIS)

    Tanaka, Yoshihisa; Mori, Seiji

    1979-01-01

    The irradiation damage analysis system using a damage function was investigated. This irradiation damage analysis system consists of the following three processes, the unfolding of a damage function, the calculation of the neutron flux spectrum of the object of damage analysis and the estimation of irradiation effect of the object of damage analysis. The damage function is calculated by applying the SAND-2 code. The ANISN and DOT3, 5 codes are used to calculate neutron flux. The neutron radiation and the allowable time of reactor operation can be estimated based on these calculations of the damage function and neutron flux. The flow diagram of the process of analyzing irradiation damage by a damage function and the flow diagram of SAND-2 code are presented, and the analytical code for estimating damage, which is determined with a damage function and a neutron spectrum, is explained. The application of the irradiation damage analysis system using a damage function was carried out to the core support structure of a fast breeder reactor for the damage estimation and the uncertainty evaluation. The fundamental analytical conditions and the analytical model for this work are presented, then the irradiation data for SUS304, the initial estimated values of a damage function, the error analysis for a damage function and the analytical results are explained concerning the computation of a damage function for 10% total elongation. Concerning the damage estimation of FBR core support structure, the standard and lower limiting values of damage, the permissible neutron flux and the allowable years of reactor operation are presented and were evaluated. (Nakai, Y.)

  17. Radiation damage in DNA

    International Nuclear Information System (INIS)

    Lafleur, V.

    1978-01-01

    A number of experiments are described with the purpose to obtain a better insight in the chemical nature and the biological significance of radiation-induced damage in DNA, with some emphasis on the significance of alkali-labile sites. It is shown that not only reactions of OH radicals but also of H radicals introduce breaks and other inactivating damage in single-standed phiX174 DNA. It is found that phosphate buffer is very suitable for the study of the reactions of H radicals with DNA, as the H 2 PO 4 - ions convert the hydrated electrons into H radicals. The hydrated electron, which does react with DNA, does not cause a detectable inactivation. (Auth.)

  18. Radiation damage to histones

    International Nuclear Information System (INIS)

    Mee, L.K.; Adelstein, S.J.

    1985-01-01

    The damage to histones irradiated in isolation is being elaborated to aid the identification of the crosslinking sites in radiation-induced DNA-histone adducts. Histones are being examined by amino acid analysis to determine the destruction of residues and by polyacrylamide gel electrophoresis to delineate changes in conformation. For the slightly lysine-rich histone, H2A, a specific attack on selective residues has been established, the aromatic residues, tyrosine and phenylalanine, and the heterocyclic residue, histidine, being significantly destroyed. In addition, a significant increase in aspartic acid was found; this may represent a radiation product from scission of the ring in the histidine residues. The similarity of the effects on residues in nitrous oxide-saturated and nitrogen-saturated solutions suggests that OH . and e/sub aq//sup -/ are equally efficient and selective in their attack. On gel electrophoresis degradation of the histone H2A was found to be greatest for irradiations in nitrous oxide-saturated solutions, suggesting CH . is the most effective radical for producing changes in conformation; O/sub 2//sup -/ was essentially ineffective. Other histones are being examined for changes in amino acid composition, conformation, and for the formation of radiation products

  19. Radiation damage of light guide fibers in gamma radiation field - on-line monitoring of absorption centers formation

    International Nuclear Information System (INIS)

    Blaha, J.; Simane, C.; Finger, M.; Slunecka, M.; Finger, M. Jr.; Sluneckova, V.; Janata, A.; Vognar, M.; Sulc, M.

    2004-01-01

    The kinetics of radiation-induced changes of absorption coefficient was studied by online transmission spectra measurement for two different Kuraray light guide fibers. The samples were irradiated by bremsstrahlung gamma radiation, dose rates were from 2 Gy/s to 25 Gy/s. The kinetic coefficients both for absorption centers formation and for recovery processes were calculated. Good agreement of experimental data and simple one-short-lived absorption center model were received for radiation-hard light guide Kuraray (KFC). The more complicated process was observed on Kuraray (PSM) clear fiber. It was caused by the reaction of the oxygen dissolved in fiber and created radicals. The results are very useful for prediction of an optical fibers response in conditions of new nuclear and particle physics experiments. (author)

  20. Corneal Damage from Infrared Radiation

    National Research Council Canada - National Science Library

    McCally, Russell

    2000-01-01

    ...) laser radiation at 10.6 (micrometer) and Tm: YAG laser radiation at 2.02 (micrometer). Retinal damage from sources with rectangular irradiance distributions was also modeled. Thresholds for CO(2...

  1. Radiation Damage in Scintillating Crystals

    CERN Document Server

    Zhu Ren Yuan

    1998-01-01

    Crystal Calorimetry in future high energy physics experiments faces a new challenge to maintain its precision in a hostile radiation environment. This paper discusses the effects of radiation damage in scintillating crystals, and concludes that the predominant radiation damage effect in crystal scintillators is the radiation induced absorption, or color center formation, not the loss of the scintillation light yield. The importance of maintaining crystal's light response uniformity and the feasibility to build a precision crystal calorimeter under radiation are elaborated. The mechanism of the radiation damage in scintillating crystals is also discussed. While the damage in alkali halides is found to be caused by the oxygen or hydroxyl contamination, it is the structure defects, such as oxygen vacancies, cause damage in oxides. Material analysis methods used to reach these conclusions are presented in details.

  2. Monitoring of radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service.

  3. Monitoring of radiation exposure

    International Nuclear Information System (INIS)

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service

  4. Radiation damage in biomolecular systems

    CERN Document Server

    Fuss, Martina Christina

    2012-01-01

    Since the discovery of X-rays and radioactivity, ionizing radiations have been widely applied in medicine both for diagnostic and therapeutic purposes. The risks associated with radiation exposure and handling led to the parallel development of the field of radiation protection. Pioneering experiments done by Sanche and co-workers in 2000 showed that low-energy secondary electrons, which are abundantly generated along radiation tracks, are primarily responsible for radiation damage through successive interactions with the molecular constituents of the medium. Apart from ionizing processes, which are usually related to radiation damage, below the ionization level low-energy electrons can induce molecular fragmentation via dissociative processes such as internal excitation and electron attachment. This prompted collaborative projects between different research groups from European countries together with other specialists from Canada,  the USA and Australia. This book summarizes the advances achieved by these...

  5. Modular remote radiation monitor

    International Nuclear Information System (INIS)

    Lacerda, Fabio; Farias, Marcos S.; Aghina, Mauricio A.C.; Oliveira, Mauro V.

    2013-01-01

    The Modular Remote Radiation Monitor (MRRM) is a novel radiation monitor suitable for monitoring environmental exposure to ionizing radiation. It is a portable compact-size low-power microprocessor-based electronic device which provides its monitoring data to other electronic systems, physically distant from it, by means of an electronic communication channel, which can be wired or wireless according to the requirements of each application. Besides its low-power highly-integrated circuit design, the Modular Remote Radiation Monitor is presented in a modular architecture, which promotes full compliance to the technical requirements of different applications while minimizing cost, size and power consumption. Its communication capability also supports the implementation of a network of multiple radiation monitors connected to a supervisory system, capable of remotely controlling each monitor independently as well as visualizing the radiation levels from all monitors. A prototype of the MRRM, functionally equivalent to the MRA-7027 radiation monitor, was implemented and connected to a wired MODBUS network of MRA-7027 monitors, responsible for monitoring ionizing radiation inside Argonauta reactor room at Instituto de Engenharia Nuclear. Based on the highly positive experimental results obtained, further design is currently underway in order to produce a consumer version of the MRRM. (author)

  6. Neutron induced radiation damage

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1977-01-01

    We derive a general expression for the number of displaced atoms of type j caused by a primary knock-on of type i. The Kinchin-Pease model is used, but considerably generalised to allow for realistic atomic potentials. Two cases are considered in detail: the single particle problem causing a cascade and the neutron initiated problem which leads to multiple subcascades. Numerical results have been obtained for a variety of scattering laws. An important conclusion is that neutron initiated damage is much more severe than atom-initiated damage and leads to the number of displaced atoms being a factor of (A+1) 2 /4A larger than the single primary knock-on theory predicts. A is the ratio of the atomic mass to the neutron mass. The importance of this result to the theory of neutron sputtering is explained. (orig.) [de

  7. Radiation protection and monitoring

    International Nuclear Information System (INIS)

    Thomas, P.

    1982-01-01

    The present paper deals with the following topics: - Radiological quantities and units - Principles of radiological protection - Limits of doses and activity uptake - Activity discharges and monitoring - Radiation exposure and its calculation - Environmental monitoring - Personnel dosimetry. (orig./RW)

  8. Radiation Damage and Dimensional Changes

    International Nuclear Information System (INIS)

    El-Barbary, A.A.; Lebda, H.I.; Kamel, M.A.

    2009-01-01

    The dimensional changes have been modeled in order to be accommodated in the reactor design. This study has major implications for the interpretation of damage in carbon based nuclear fission and fusion plant materials. Radiation damage of graphite leads to self-interstitials and vacancies defects. The aggregation of these defects causes dimensional changes. Vacancies aggregate into lines and disks which heal and contract the basal planes. Interstitials aggregate into interlayer disks which expand the dimension

  9. Radiation-induced liver damage

    International Nuclear Information System (INIS)

    Marcial, V.A.; Santiago-Delpin, E.A.; Lanaro, A.E.; Castro-Vita, H.; Arroyo, G.; Moscol, J.A.; Gomez, C.; Velazquez, J.; Prado, K.

    1977-01-01

    Due to the recent increase in the use of radiation therapy in the treatment of cancer with or without chemotherapy, the risk of liver radiation damage has become a significant concern for the radiotherapist when the treated tumour is located in the upper abdomen or lower thorax. Clinically evident radiation liver damage may result in significant mortality, but at times patients recover without sequelae. The dose of 3000 rads in 3 weeks to the entire liver with 5 fractions per week of 200 rads each, seems to be tolerated well clinically by adult humans. Lower doses may lead to damage when used in children, when chemotherapy is added, as in recent hepatectomy cases, and in the presence of pre-existent liver damage. Reduced fractionation may lead to increased damage. Increased fractionation, limitation of the dose delivered to the entire liver, and restriction of the high dose irradiation volume may afford protection. With the aim of studying the problems of hepatic radiation injury in humans, a project of liver irradiation in the dog is being conducted. Mongrel dogs are being conditioned, submitted to pre-irradiation studies (haemogram, blood chemistry, liver scan and biopsy), irradiated under conditions resembling human cancer therapy, and submitted to post-irradiation evaluation of the liver. Twenty-two dogs have been entered in the study but only four qualify for the evaluation of all the study parameters. It has been found that dogs are susceptible to liver irradiation damage similar to humans. The initial mortality has been high mainly due to non-radiation factors which are being kept under control at the present phase of the study. After the initial experiences, the study will involve variations in total dose and fractionation, and the addition of anticoagulant therapy for possible prevention of radiation liver injury. (author)

  10. Radiation damage in plastic scintillators

    International Nuclear Information System (INIS)

    Majewski, S.

    1990-01-01

    Results of radiation damage studies in plastic scintillators are reviewed and critically analyzed from the point of view of applications of plastic scintillators in calorimetric detectors for the SSC. Damage to transmission and to fluorescent yield in different conditions is discussed. New directions in R ampersand D are outlined. Several examples are given of the most recent data on the new scintillating materials made with old and new plastics and fluors, which are exhibiting significantly improved radiation resistance. With a present rate of a vigorous R D programme, the survival limits in the vicinity of 100 MRad seem to be feasible within a couple of years

  11. Environmental γ radiation monitor

    International Nuclear Information System (INIS)

    Qu Xiaopeng

    1993-01-01

    The environmental γ radiation monitor is a kind of dose or dose rate measuring devices, which can be used for monitoring environmental γ radiation around a nuclear site when normal or even abnormal events occur. The monitor is controlled by a single-chip microcomputer so that it can acquire synchronously the data from four detectors and transfer the data to a central computer. The monitor has good temperature property due to the technique of temperature correction. The monitor has been used in the environment monitoring vehicle for Qinshan Nuclear Power Plant

  12. Digital radiation monitor system

    International Nuclear Information System (INIS)

    Quan Jinhu; Zhai Yongchun; Guan Junfeng; Ren Dangpei; Ma Zhiyuan

    2003-01-01

    The article introduced digital radiation monitor system. The contents include: how to use advanced computer net technology to establish equipment net for nuclear facility, how to control and manage measuring instruments on field equipment net by local area net, how to manage and issue radiation monitoring data by internet

  13. Measurement of radiation damage on an optical reflector

    International Nuclear Information System (INIS)

    Peng, K.C.; Sahu, S.K.; Huang, H.C.; Ueno, K.; Chang, Y.H.; Wang, C.H.; Hou, W.S.

    1997-01-01

    We measured the radiation damage on an optical white fluorocarbon reflector called Goretex, which is to be used for aerogel threshold counters and crystal calorimeters of the BELLE detector of the KEK B-factory. Reflectance of the Goretex surface was monitored to see any effect of the radiation damage. Maximum equivalent dose was 8.6 Mrad. No radiation damage is observed within measurement errors. (orig.)

  14. Reusable radiation monitor

    International Nuclear Information System (INIS)

    Fanselow, D.L.; Ersfeld, D.A.

    1978-01-01

    An integrating, reusable device for monitoring exposure to actinic radiation is disclosed. The device comprises a substrate having deposited thereon at least one photochromic aziridine compound which is sealed in an oxygen barrier to stabilize the color developed by the aziridine compound in response to actinic radiation. The device includes a spectral response shaping filter to transmit only actinic radiation of the type being monitored. A color standard is also provided with which to compare the color developed by the aziridine compound

  15. Radiation monitoring system

    International Nuclear Information System (INIS)

    Takeuchi, Nobuyoshi; Fujimoto, Toshiaki; Nagama, Hideyo

    2007-01-01

    A positive outlook toward nuclear power plants and a higher level of technologies for using radiation in the medical field are trends that are spreading throughout the world, and as a consequence, demand is increasing for equipment and systems that measure and control radiation. Equipment ranging from radiation detection and measurement devices to computer-based radiation management systems will be set up in overseas. Products that depend on overseas specifications based on IEC and other international standards are being developed. Fuji Electric is advancing the overseas deployment of radiation monitoring systems by adopting measures that will ensure the reliability and traceability of radiation equipment. (author)

  16. Radiation damage in the diamond based beam condition monitors of the CMS experiment at the Large Hadron Collider (LHC) at CERN

    CERN Document Server

    Guthoff, Moritz; Dabrowski, Anne; De Boer, Wim; Stickland, David; Lange, Wolfgang; Lohmann, Wolfgang

    2013-01-01

    The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector ef fi ciency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, becaus...

  17. Radiation exposure and chromosome damage

    International Nuclear Information System (INIS)

    Lloyd, D.

    1979-01-01

    Chromosome damage is discussed as a means of biologically measuring radiation exposure to the body. Human lymphocytes are commonly used for this test since the extent of chromosome damage induced is related to the exposure dose. Several hundred lymphocytes are analysed in metaphase for chromosome damage, particularly dicentrics. The dose estimate is made by comparing the observed dicentric yield against calibration curves, previously produced by in vitro irradiation of blood samples to known doses of different types of radiation. This test is useful when there is doubt that the film badge has recorded a reasonable whole body dose and also when there is an absence of any physical data. A case of deliberate exposure is described where the chromosome damage test estimated an exposure of 152 rads. The life span of cell aberrations is also considered. Regular checks on radiotherapy patients and some accidental overdose cases have shown little reduction in the aberration levels over the first six weeks after which the damage disappears slowly with a half-life of about three years. In conclusion, chromosome studies have been shown to be of value in resolving practical problems in radiological protection. (U.K.)

  18. Radiation damage in silicon detectors

    CERN Document Server

    Lindström, G

    2003-01-01

    Radiation damage effects in silicon detectors under severe hadron and gamma-irradiation are surveyed, focusing on bulk effects. Both macroscopic detector properties (reverse current, depletion voltage and charge collection) as also the underlying microscopic defect generation are covered. Basic results are taken from the work done in the CERN-RD48 (ROSE) collaboration updated by results of recent work. Preliminary studies on the use of dimerized float zone and Czochralski silicon as detector material show possible benefits. An essential progress in the understanding of the radiation-induced detector deterioration had recently been achieved in gamma irradiation, directly correlating defect analysis data with the macroscopic detector performance.

  19. RTP Radiation Monitoring System

    International Nuclear Information System (INIS)

    Alfred, S.L.; Mohd Fairus Abdul Farid; Ahmad Nabil Abdul Rahim; Nurhayati Ramli

    2015-01-01

    Radiation Monitoring System aiming to limiting dose exposed to personnel to the lowest level referring to the concept of ALARA (As Low As Reasonably Achievable). Atomic Energy Licensing (Basic Safety Radiation Protection) Regulation 2010 (Act 304) is a baseline to control employee and public radiation protection program and guideline, as well as to meet the requirement of the Occupational Safety and Health 1994 (Act 514). (author)

  20. Development of web monitoring radiation area monitor

    International Nuclear Information System (INIS)

    Jung, Hoon Jin; Lee, Jun Hee; Namkoong, Phil; Lee, Dong Hoon; Lee, Su Hong; Lee, Gun Bae

    2005-01-01

    Recently the increasing number of radioisotope industry and nuclear facility have ever raised the possibility of radiation safety accident. As such a result, radioisotope companies and nuclear facility operators have become to be much interested in radiation area monitoring for efficient radiation protection. At present, almost of the radiation area monitors which are imported products are outdated in aspect of their functions. Diversification of the monitoring work is urgently demanding additional functions to be added. Thus we have developed new-type digital area monitor which enables remote web monitoring with image and radiation dose rate value at distant places through using internet, the latest IT technology, and radiation measurement technology

  1. Radiation damage of structural materials

    International Nuclear Information System (INIS)

    Koutsky, J.; Kocik, J.

    1994-01-01

    Maintaining the integrity of nuclear power plants (NPP) is critical in the prevention or control of severe accidents. This monograph deals with both basic groups of structural materials used in the design of light-water nuclear reactors, making the primary safety barriers of NPPs. Emphasis is placed on materials used in VVER-type nuclear reactors: Cr-Mo-V and Cr-Ni-Mo-V steel for reactor pressure vessels (RPV) and Zr-Nb alloys for fuel element cladding. The book is divided into seven main chapters, with the exception of the opening one and the chapter providing phenomenological background for the subject of radiation damage. Chapters 3-6 are devoted to RPV steels and chapters 7-9 to zirconium alloys, analyzing their radiation damage structure, changes of mechanical properties due to neutron irradiation as well as factors influencing the degree of their performance degradation. The recovery of damaged materials is also discussed. Considerable attention is paid to a comparison of VVER-type and western-type light-water materials

  2. Radiation damage in the diamond based beam condition monitors of the CMS experiment at the Large Hadron Collider (LHC) at CERN

    Science.gov (United States)

    Guthoff, Moritz; Afanaciev, Konstantin; Dabrowski, Anne; de Boer, Wim; Lange, Wolfgang; Lohmann, Wolfgang; Stickland, David

    2013-12-01

    The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector efficiency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, because of the high number of low energy neutrons in these regions. The signal decrease was stronger than expected from the number of simulated defects. Here polarization from trapped charge carriers in the defects is a likely candidate for explaining the difference, as suggested by Transient Current Technique (TCT) measurements. A single-crystalline (sCVD) diamond sensor shows a faster relative signal decrease than a pCVD sensor mounted at the same location. This is expected, since the relative increase in the number of defects is larger in sCVD than in pCVD sensors.

  3. Radiation contamination monitors

    International Nuclear Information System (INIS)

    Kato, Tsutomu; Iba, Hiroshi; Sato, Hiroshi

    1999-01-01

    To make sure of no contamination on people, used articles and working uniforms coming out of the radiation controlled area, nuclear power plants are equipped with radioactive contamination monitors. This paper outlines the basic specifications and advantages of our personnel surface contamination monitors to inspect whole-body surface contamination of people coming out, article surface contamination monitors to inspect the surface and inside contamination of used articles brought out, laundry monitors to inspect surface contamination of working uniforms used in the area before and after a wash, and whole-body counters to inspect and measure the internal contamination of a person out of the area. (author)

  4. Calibration of radiation monitoring instruments

    International Nuclear Information System (INIS)

    1973-01-01

    Radiation protection is dependent on good radiation monitoring, and properly calibrated instruments are essential for this work. Simple procedures for periodically checking and recalibrating different kinds of radiation monitoring instruments are shown in this training film

  5. Calibration of radiation monitoring instruments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1974-12-31

    Radiation protection is dependent on good radiation monitoring, and properly calibrated instruments are essential for this work. Simple procedures for periodically checking and recalibrating different kinds of radiation monitoring instruments are shown in this training film

  6. Radiation damage of structural materials

    CERN Document Server

    Koutsky, Jaroslav

    1994-01-01

    Maintaining the integrity of nuclear power plants is critical in the prevention or control of severe accidents. This monograph deals with both basic groups of structural materials used in the design of light-water nuclear reactors, making the primary safety barriers of NPPs. Emphasis is placed on materials used in VVER-type nuclear reactors: Cr-Mo-V and Cr-Ni-Mo-V steel for RPV and Zr-Nb alloys for fuel element cladding. The book is divided into 7 main chapters, with the exception of the opening one and the chapter providing a phenomenological background for the subject of radiation damage. Ch

  7. Damages by radiation in glasses

    International Nuclear Information System (INIS)

    Olguin, F.; Gutierrez, C.; Cisniega, G.; Flores, J.H.; Golzarri, J.I.; Espinoza, G.

    1997-01-01

    As a part of the works carried out to characterize the electrons beam from the Pelletron accelerator of the Mexican Nuclear Center aluminium-silicate glass samples were irradiated. The purpose of these irradiations is to cause alterations in the amorphous microstructure of the material by means of the creation of color centers. The population density of these defects, consequence to the irradiation, is function of the exposure time which varied from 1 to 30 minutes, with an electronic beam energy of 400 keV, doing the irradiations at free atmosphere. the obtained spectra are correlated by damage which the radiation produced. (Author)

  8. Health effects of radiation damage

    International Nuclear Information System (INIS)

    Gasimova, K; Azizova, F; Mehdieva, K.

    2012-01-01

    Full text : A summary of the nature of radiactive contamination would be incomplete without some mention of the human health effects relatied to radioactivity and radioactive materials. Several excellent reviews at the variety of levels of detail have been written and should be consulted by the reader. Internal exposures of alpha and beta particles are important for ingested and inhaled radionuclides. Dosimetry models are used to estimate the dose from internally deposited radioactive particles. As mentioned above weighting parameters that take into account the radiation type, the biological half-life and the tissue or organ at risk are used to convert the physically absorbed dose in units of gray (or red) to the biologically significant committed equivalent dose and effective dose, measured in units of Sv (or rem). There is considerable controversy over the shape of the dose-response curve at the chronic low dose levels important for enviromental contamination. Proposed models include linear models, non-linear models and threshold models. Because risks at low dose must be extrapolated from available date at high doses, the shape of the dose-response curve has important implications for the environmental regulations used to protect the general public. The health effect of radiation damage depends on a combination of events of on the cellular, tissue and systemic levels. These lead to mutations and cellular of the irradiated parent cell. The dose level at which significant damage occurs depends on the cell type. Cells that reproduce rapidily, such as those found in bone marrow or the gastrointestinal tract, will be more sensitive to radiation than those that are longer lived, such as striated muscle or nerve cells. The effects of high radiation doses on an organ depends on the various cell types it contains

  9. Radiation damage to DNA constituents

    International Nuclear Information System (INIS)

    Bergene, R.

    1977-01-01

    The molecular changes of the DNA molecule, in various systems exposed to inoizing radiation, have been the subject of a great number of studies. In the present work electron spin resonance spectroscopy (ESR) has been applied to irradiated crystalline systems, in particular single crystals of DNA subunits and their derivatives. The main conclusions about the molecular damage are based on this technique in combination with molecular orbital calculations. It should be emphasized that the ESR technique is restricted to damage containing unpaired electrons. These unstable intermediates called free radicals seem, however, to be involved in all molecular models describing the action of radiation on DNA. One of the premises for a detailed theory of the radiation induced reactions at the physico-chemical level seems to involve exact knowledge of the induced free radicals as well as the modes of their formation and fate. For DNA, as such, it is hardly possible to arrive at such a level of knowledge since the molecular complexity prevents selective studies of the many different radiation induced products. One possible approach is to study the free radicals formed in the constituents of DNA. In the present work three lines of approach should be mentioned. The first is based on the observation that radical formation in general causes only minor structural alterations to the molecule in question. The use of isotopes with different spin and magnetic moment (in particular deuterium) may also serve a source of information. Deuteration leads to a number of protons, mainly NH - and OH, becoming substituted, and if any of these are involved in interactions with unpaired protons the resonance pattern is influeneed. The third source of information is molecular orbital calculation. The electron spin density distribution is a function in the three dimensional space based on the system's electronic wave functions. This constitutes the basis for the idea that ESR data can be correlated with

  10. Routine sanitary radiation monitoring

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Hygienic bases and organization principles of radiation monitoring realized in the process of operation of nuclear power engineering enterprises are considered. The monitoring is aimed at prevention from a negative effect of ionizing radiations on public heath. It is achieved by solution of the following tasks: realization of control over radioactive waste disposal into environment, control over the level of radioactive substance content in evironmental objects, control over external and internal irradiation of population assessment of environmental radiactivity of certain regions and of the territory of the country with the subsequent informing the corresponding organizations and population

  11. Environmental radiation monitoring system

    International Nuclear Information System (INIS)

    Kato, Tsutomu; Shioiri, Masatoshi; Sakamaki, Tsuyoshi

    2007-01-01

    Environmental radiation monitoring systems are used to measure and monitoring gamma-rays at the observation boundaries of nuclear facilities and in the surrounding areas. In recent years, however, few new nuclear facilities have been constructed and the monitoring systems shift to renewal of existing systems. In addition, in order to increase public acceptance, the facilities are being equipped with communication lines to provide data to prefectural environmental centers. In this text, we introduce the latest technology incorporated in replacement of environmental radiation monitoring systems. We also introduce a replacement method that can shorten the duration during which environmental dose rate measurement is interrupted by enabling both the replacement system and the system being replaced to perform measurements in parallel immediately before and after the replacement. (author)

  12. Radiation damage in lithium orthosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Noda, K.; Nakazawa, T.; Ishii, Y.; Fukai, K.; Watanabe, H. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment); Matsui, H.; Vollath, D.

    1993-11-01

    Radiation damage in lithium orthosilicate (Li[sub 4]SiO[sub 4]) and Al-doped Li[sub 4]SiO[sub 4] (Li[sub 3.7]Al[sub 0.1]SiO[sub 4]) irradiated with oxygen ions was studied with ionic conductivity measurements, Raman spectroscopy, Fourier transform infrared photo-acoustic spectroscopy (FT-IR PAS) and transmission electron microscopy. It was seen from the ionic conductivity measurements that lithium-ion vacancies were introduced as irradiation defects for Li-ions sites in both materials due to the irradiation. By the Raman spectroscopy, oxygen atoms in SiO[sub 4] tetrahedra were considered to be preferentially displaced due to the irradiation for Li[sub 4]SiO[sub 4], although only a decrease of the number of SiO[sub 4] tetrahedra occurred for Li[sub 3.7]Al[sub 0.1]SiO[sub 4] by displacement of both silicon and oxygen atoms. Decomposition of SiO[sub 4] tetrahedra and formation of some new phases having Si-O-Si and Si-O bonds were found to take place for both Li[sub 4]SiO[sub 4] and Li[sub 3.7]Al[sub 0.1]SiO[sub 4] by FT-IR PAS. In the electron microscopy, damage microstructure consisting of many voids or cavities and amorphization were observed for Li[sub 4]SiO[sub 4] irradiated with oxygen ions. The recovery behavior of radiation damage mentioned above was also investigated. (author).

  13. Personal radiation monitoring

    International Nuclear Information System (INIS)

    Julius, H.W.

    1976-01-01

    This report reviews the context of a primary university course in individual radiation monitoring. A brief account of the regulations and permissible doses is given. The principles and design of film dosemeters, thermoluminescent dosemeters and the whole-body counting technique are treated

  14. Radiation monitoring by minicomputer

    International Nuclear Information System (INIS)

    Seamons, M.

    1977-01-01

    Radiation monitoring at the Los Alamos Scientific Laboratory (LASL) ranges from measuring the potential build-up of alpha particle radiation in the offices and laboratories of LASL to the detection of radiation leakage from nuclear tests at the Nevada Test Site (NTS). This paper describes PDP-11 based systems to accomplish both types of monitoring. In the first system, filter papers are collected from monitoring stations around LASL. One filter paper is placed under any of 128 photomultiplier (PM) tubes exposing it to alpha radiation. Alpha particle ''hits'' are recorded in a 64-word hardware FIFO, which interrupts and is read by the computer. The FIFO makes it possible to handle short aggregate alpha particle bursts of up to 10 6 hits/s in a computer that can only process 10 4 hits/s. In the second system, up to 100 current measuring radiation probes feed data from the site of the nuclear test(s) to the computer by microwave. The software system can support three tests simultaneously. Both systems offer a high degree of flexibility in configuring for a new test and in real-time control of such things as channel assignment, selective data retrieval, and output formatting

  15. Radiation-induced damage of membranes

    International Nuclear Information System (INIS)

    Yonei, Shuji

    1977-01-01

    An outline of membranous structure was stated, and radiation-induced damage of membranes were surveyed. By irradiation, permeability of membranes, especially passive transportation mechanism, was damaged, and glycoprotein in the surface layers of cells and the surface layer structures were changed. The intramembranous damage was induced by decrease of electrophoresis of nuclear mambranes and a quantitative change of cytochrome P450 of microsomal membranes of the liver, and peroxidation of membranous lipid and SH substitute damage of membranous protein were mentioned as the mechanism of membranous damage. Recovery of membranous damage depends on radiation dose and temperature, and membranous damage participates largely in proliferation death. (tsunoda, M.)

  16. Radiation monitoring device

    International Nuclear Information System (INIS)

    Sato, Toshifumi.

    1993-01-01

    The device of the present invention concerns a reactor start-up region monitor of a nuclear power plant. In an existent start-up region monitor, bias voltage is limited, if the reactor moves to a power region, in order to prevent degradation of radiation detectors. Accordingly, since the power is lower than an actual reactor power, the reactor power can not be monitored. The device of the present invention comprises a memory means for previously storing a Plateau's characteristic of the radiation detectors and a correction processing means for obtaining a correction coefficient in accordance with the Plateau's characteristic to correct and calculate the reactor power when the bias voltage is limited. With such a constitution, when the reactor power exceeds a predetermined value and the bias voltage is limited, the correction coefficient can be obtained by the memory means and the correction processing means. Corrected reactor power can also be obtained from the start-up region monitor by the correction coefficient. As a result, monitoring of the reactor power can be continued while preventing degradation of the radiation detector even if the bias voltage is limited. (I.S.)

  17. Radiation damages in solids and tissues

    International Nuclear Information System (INIS)

    Cevc, P.; Kogovsek, F.; Kanduser, A.; Peternelj, M.; Skaleric, U.; Funduk, N.

    1977-01-01

    In submitted research work we have studied radiation damages in ferroelectric crystals and application of ferroelectric crystals. Studying the radiation damages we have introduced new technique of EPR measurements under high hydrostatic pressure, that will enable us to obtain additional data on crystal lattice dynamics. A change of piroelectric coefficient with high radiation doses in dopped TGS has been measured also

  18. Radiation damages in superconducting materials

    International Nuclear Information System (INIS)

    Heinz, W.; Seibt, E.

    1978-01-01

    Radiation damage investigations of technical superconductors are reported and discussed with respect to their main properties like critical current jsub(c), transition temperature Tsub(c), upper critical field Bsub(c2), pinning and annealing behaviour. Ordered A15 type alloys (like Nb 3 Sn and V 3 Ga) show significant reductions of all critical parameters above a threshold of about 2x10 21 m -2 with 50 MeV deuterons corresponding to 2x10 22 neutrons/m 2 (Esub(n)>0.1 MeV). Pure metals and disordered B1 type alloys (like Nb or NbTi) show only a small linear decrease in critical parameters (except Bsub(c2) of niobium). Experimental results are compared with theoretical calculations. (author)

  19. Radiation monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    Aghina, Mauricio A.C.; Farias, Marcos S. de; Lacerda, Fabio de; Heimlich, Adino [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Design of a portable low-power multichannel analyzer with wireless connectivity for remote radiation monitoring, powered from a solar panel with a internal battery to be operated in field. The multichannel analyzer is based on a single microcontroller which performs the digital functions and an analog signal processing board for implementing a Gaussian shaper preamplifier, a Gaussian stretcher, sample and hold, pile-up rejector and a 10 bit ADC. Now this design is to be used with a NaI(Ti) scintillator detector. This multichannel analyzer is designed to be a part of radiation monitoring network. All of them are connected, by radio in a radius of 10 kilometers, to a supervisor computer that collects data from the network of multichannel analyzers and numerically display the latest radiation measurements or graphically display measurements over time for all multichannel analyzers. Like: dose rate, spectra and operational status. Software also supports remotely configuring operating parameters (such as radiation alarm level) for each monitor independently. (author)

  20. Radiation monitoring system

    International Nuclear Information System (INIS)

    Aghina, Mauricio A.C.; Farias, Marcos S. de; Lacerda, Fabio de; Heimlich, Adino

    2015-01-01

    Design of a portable low-power multichannel analyzer with wireless connectivity for remote radiation monitoring, powered from a solar panel with a internal battery to be operated in field. The multichannel analyzer is based on a single microcontroller which performs the digital functions and an analog signal processing board for implementing a Gaussian shaper preamplifier, a Gaussian stretcher, sample and hold, pile-up rejector and a 10 bit ADC. Now this design is to be used with a NaI(Ti) scintillator detector. This multichannel analyzer is designed to be a part of radiation monitoring network. All of them are connected, by radio in a radius of 10 kilometers, to a supervisor computer that collects data from the network of multichannel analyzers and numerically display the latest radiation measurements or graphically display measurements over time for all multichannel analyzers. Like: dose rate, spectra and operational status. Software also supports remotely configuring operating parameters (such as radiation alarm level) for each monitor independently. (author)

  1. Environmental radiation monitoring

    International Nuclear Information System (INIS)

    Watanabe, Isao

    2011-01-01

    The samples, pretreatment method, and measurement methods of 'Environmental radioactivity level by prefecture' of Ministry of Education, Culture, Sports, Science and Education (MEXT) is explained. It consists of 1), 'Environmental radioactivity level by prefecture' in normal period, 2) 'Strengthening of Monitoring of Environmental Radioactivity Level by Prefecture' of MEXT at emergency 3) strengthening of monitoring by Fukushima Daiichi nuclear accident, 4) radiation monitoring around the nuclear facility, 5) strengthening of monitoring by MEXT, and 6) quality of monitoring. The survey item and samples etc., of 'Environmental radioactivity level by prefecture', monitoring post, NaI (Tl) scintillation survey meter, sampling and pretreatment methods for radionuclide analysis in normal period, an example of germanium semiconductor detector, gamma ray spectrum of spaghetti from Italy by germanium semiconductor detector, flow chart of radionuclide analysis of fallout in normal period and emergency by germanium semiconductor detector, example of analytical method of radioactive strontium ( ion exchange method), outline of plutonium analytical method for emergency, sampling and pretreatment methods of radionuclides for strengthening, monitoring result around Fukushima Daiichi nuclear plant from June 23 to 24, 2011, change of air dose rate of monitoring post in Mito city from March 14 to 26, 2011, concentration of I-131 and Cs-137 in fallout in Hitachinaka city from March 19 to April 30, 2011, and change of concentration of I-131, Cs-134 and Cs-137 in tap water of Iitate village from March 20 to April 30, 2011, are illustrated. (S.Y.)

  2. Community Radiation Monitoring Program

    International Nuclear Information System (INIS)

    Lucas, R.P. Jr.; Cooper, E.N.; McArthur, R.D.

    1990-05-01

    The Community Radiation Monitoring Program began its ninth year in the summer of 1989, continuing as an essential portion of the Environmental Protection Agency's long-standing off-site monitoring effort. It is a cooperative venture between the Department of Energy (DOE), the Environmental Protection Agency (EPA), the University of Utah (U of U), and the Desert Research Institute (DRI) of the University of Nevada System. The objectives of the program include enhancing and augmenting the collection of environmental radiation data at selected sites around the Nevada Test Site (NTS), increasing public awareness of that effort, and involving, in as many ways as possible, the residents of the off-site area in these and other areas related to testing nuclear weapons. This understanding and improved communication is fostered by hiring residents of the communities where the monitoring stations are located as program representatives, presenting public education forums in those and other communities, disseminating information on radiation monitoring and related subjects, and developing and maintaining contacts with local citizens and elected officials in the off-site areas. 8 refs., 4 figs., 4 tabs

  3. Radiation damage in the diamond based beam condition monitors of the CMS experiment at the Large Hadron Collider (LHC) at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Guthoff, Moritz, E-mail: moritz.guthoff@cern.ch [CERN, 1211 Genève 23 (Switzerland); Institut für Experimentelle Kernphysik, Karlsruhe Institute of Technology, Campus Süd, P.O. Box 6980, 76128 Karlsruhe (Germany); Afanaciev, Konstantin [DESY, Platanenallee 6, 15738 Zeuthen (Germany); NC PHEP BSU, Minsk (Belarus); Dabrowski, Anne [CERN, 1211 Genève 23 (Switzerland); Boer, Wim de [Institut für Experimentelle Kernphysik, Karlsruhe Institute of Technology, Campus Süd, P.O. Box 6980, 76128 Karlsruhe (Germany); Lange, Wolfgang [DESY, Platanenallee 6, 15738 Zeuthen (Germany); Lohmann, Wolfgang [DESY, Platanenallee 6, 15738 Zeuthen (Germany); Brandenburgische Technische Universität, Postfach 101344, 03013 Cottbus (Germany); Stickland, David [Princeton University, Princeton, NJ 08544-0708 (United States)

    2013-12-01

    The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector efficiency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, because of the high number of low energy neutrons in these regions. The signal decrease was stronger than expected from the number of simulated defects. Here polarization from trapped charge carriers in the defects is a likely candidate for explaining the difference, as suggested by Transient Current Technique (TCT) measurements. A single-crystalline (sCVD) diamond sensor shows a faster relative signal decrease than a pCVD sensor mounted at the same location. This is expected, since the relative increase in the number of defects is larger in sCVD than in pCVD sensors. -- Highlights: •The BCM system and its diamond detectors at the CMS experiment of the LHC are presented. •Detectors show a decreased signal strength with increasing integrated luminosity. •CCD measurements using constant HV and alternating HV to prevent polarization are compared. •TCT measurements show a decreasing signal when polarization builds up. •Polarization effects are a likely

  4. Radiation damage in the diamond based beam condition monitors of the CMS experiment at the Large Hadron Collider (LHC) at CERN

    International Nuclear Information System (INIS)

    Guthoff, Moritz; Afanaciev, Konstantin; Dabrowski, Anne; Boer, Wim de; Lange, Wolfgang; Lohmann, Wolfgang; Stickland, David

    2013-01-01

    The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector efficiency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, because of the high number of low energy neutrons in these regions. The signal decrease was stronger than expected from the number of simulated defects. Here polarization from trapped charge carriers in the defects is a likely candidate for explaining the difference, as suggested by Transient Current Technique (TCT) measurements. A single-crystalline (sCVD) diamond sensor shows a faster relative signal decrease than a pCVD sensor mounted at the same location. This is expected, since the relative increase in the number of defects is larger in sCVD than in pCVD sensors. -- Highlights: •The BCM system and its diamond detectors at the CMS experiment of the LHC are presented. •Detectors show a decreased signal strength with increasing integrated luminosity. •CCD measurements using constant HV and alternating HV to prevent polarization are compared. •TCT measurements show a decreasing signal when polarization builds up. •Polarization effects are a likely

  5. Radiation monitoring around accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Shinichi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan)

    2000-07-01

    The present status of a network of radiation monitors (NORM) working at KEK is described in detail. NORM consists of there parts; stand-alone radiation monitors (SARM), local-monitoring stations (STATION) and a central data-handling system (CENTER). NORM has developed to a large-scaled monitoring system in which more than 250 SARMs are under operation for monitoring the radiation fields and radioactivities around accelerators in KEK. (author)

  6. Metamict state radiation damage in crystalline materials

    International Nuclear Information System (INIS)

    Haaker, R.F.; Ewing, R.C.

    1979-01-01

    Metamict minerals provide an excellent basis for the evaluation of long-term radiation damage effects, particularly such changes in physical and chemical properties as microfracturing, hydrothermal alteration, and solubility. This paper summarizes pertinent literature on metamictization and proposes experiments that are critical to the elucidation of structural controls on radiation damage in crystalline phases

  7. [Mechanisms of electromagnetic radiation damaging male reproduction].

    Science.gov (United States)

    Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

    2012-08-01

    More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

  8. Repair of radiation damage in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis.

  9. Nature of radiation damage in ceramics

    International Nuclear Information System (INIS)

    Bunch, J.M.

    1976-01-01

    Efforts to determine the equivalence between different sources of radiation damage in ceramics are reviewed. The ways in which ceramics differ from metals are examined and proposed mechanisms for creation and stabilization of defects in insulators are outlined. Work on radiation damage in crystalline oxides is summarized and suggestions for further research are offered

  10. Repair of radiation damage in mammalian cells

    International Nuclear Information System (INIS)

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis

  11. Remote radiation environmental monitoring

    International Nuclear Information System (INIS)

    Pashayev, A.M.; Mehdiyev, A.Sh.; Bayramov, A.A.

    2003-01-01

    Full text: The project of the automated remote monitoring for a level of an environment background radiation in settlements along boundary of the Azerbaijan Republic is developed. The main purpose of the project is: increase of a level of a radiation safety on territory of the Azerbaijan Republic; controlling of a level of an environment background radiation on boundary of the Azerbaijan Republic with the purpose of well-timed warning and acceptance of indispensable measures at probable emergencies on Atomic Power Stations in a number adjacent from Azerbaijan countries, or other ecological catastrophes; controlling of a level of an environment background radiation along eastern suburbs of Azerbaijan regions occupied of Armenia's army and detection of the facts of wrongful disposals of atomic engineering of Armenia on territory of Azerbaijan. As is known, in a number adjacent from Azerbaijan countries the nuclear industry is advanced or develops. It has resulted in origin of threat of a radiation hazard in case of ecological catastrophes: widely scale leakage of radioactive wastes, explosions, or fires on nuclear generating sets, acts of sabotage, directional against Azerbaijan. In this case, at unfavorable meteorological conditions a radioactive waste may be brought by a wind or a rain on territory of Azerbaijan. Measurement is supposed a carry with the help of 'EKOMON' fixed stations. The results of round-the-clock a gamma and a neutron background measurement from the stations will be transmitted automatically to a dispatcher station in the central computer. Established on the stations telescopic sensors also will allow to determine a direction of a radiation and coordinates of radiation source. Stations will be located along boundary, and also in Kedabek, Akstafa, Terter, Agdam and Fizuli regions, and in Autonomous Republic of Nakhichevan

  12. Dermal damage from ultraviolet radiation

    International Nuclear Information System (INIS)

    Kligman, L.H.

    1988-01-01

    Ultraviolet (UV) radiation is increasingly recognized as the cause of a vast number of changes in the skin of humans and animals. These include alterations at the molecular, cellular, tissue and systematic levels. In the recent past, much has been learned about the immediate effects in skin of acute UV exposure (i.e. sunburn) with its epidermal cell death, inflammation and vasolidation. With chronic exposure, many of the clinical and histologic effects can be seen only after decades. Visually, these are hyper- and hypopigmented macules, dry scaly, wrinkled skin with a variety of benign, pre-malignant and malignant neoplasms. All epidermal in origin, they lead, inexorably in humans, to the appearance the authors described as photo-aged. Underlying many of these visible manifestations are drastic changes in the dermis. These relate chiefly to destruction of mature collagen, with a compensatory overproduction of reticulin fibers, hyperplasia of elastic fibers eventuating in elastosis, increased levels of the glycosaminoglycans (GAGs) comprising the ground substance and changes in the microvasculature. First described in actinically damaged humans, systematic investigation required an animal model

  13. Radiation protection and monitoring

    International Nuclear Information System (INIS)

    Bruecher, L.; Langmueller, G.; Tuerschmann, G.

    1997-01-01

    The safety, the quality and efficiency of the radiological monitoring systems for block one and two of the NPP Mochovce, designed and delivered by the general designer, should be increased by EUCOM Siemens. Modern, accident resistant and/or more powerful monitoring systems have been designed by Siemens will be added to the existing systems. To achieve this radiation measuring units will be installed inside the hermetic zone, in the reactor hall, at the stack, at the release water system and in the environment in the vicinity of the NPP. The presentation, the storage distribution and the processing of all measuring results also will be optimised by installing a modern high-performance computer system, the so-called Central Radiological Computer System 'CRCS', featuring a high availability. The components will be installed in the relevant control rooms all over the plant. With this computer system it is easy to control the radiation level inside and outside the NPP during normal operation and during and after an accident. Special programs, developed by Siemens support the staff by interpreting the consequences of radioactive releases into the environment and by initiating protection procedures during and after an accident. All functions of the system are available for emergency protection drills and training the staff interruption of the normal control procedure. For the personal protection a digital personal dosimetry system completely considering with the requirements of ICRP 60 and several contamination monitors will be installed. (authors)

  14. Radiation damage analysis by positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Siegel, R.W.

    1982-01-01

    Positron annihilation spectroscopy (PAS) has in recent years become a valuable new tool for investigating defects in metals. The ability of the positron to localize in a trapped state at various defect sites, in which the positron annihilates with unique characteristics, has enabled the positron to be used as a localized probe of these defect sites. Several reviews of the application of PAS to the study of defects in metals have been published, as have more general treatises on the applications of positron annihilation to the study of solids. PAS has made, and has considerably greater potential for, a significant contribution to radiation damage analysis in two areas of importance: (1) the determination of atomic-defect properties, a knowledge of which is necessary for the modeling required to couple the results of model experiments using electron and ion irradiation with the expected irradiation conditions of reactor systems, and (2) the monitoring and characterization of irradiation-induced microstructure development. A unique aspect of PAS for radiation damage analysis is the defect specificity of the annihilation characteristics of a trapped positron. In addition to its value as an independent analytical tool, PAS can be a useful complement to more traditional techniques for defect studies

  15. Radiation damage in semiconductor detectors

    International Nuclear Information System (INIS)

    Kraner, H.W.

    1981-12-01

    A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced

  16. Advances in SSTR techniques for dosimetry and radiation damage measurements

    International Nuclear Information System (INIS)

    Gold, R.; Roberts, J.H.; Ruddy, F.H.

    1979-01-01

    Solid state track recorders (SSTR) have been applied in the diverse nuclear reactor research. Two recent advances are described which possess outstanding relevance for reactor research, namely the evolvement of SSTR radiation damage monitors and the development of CR-39, a new plastic SSTR of extremely high sensitivity. Results from high fluence irradiations of natural quartz crystal SSTR are used to illustrate the concept of the SSTR radiation damage monitor. Response characteristics of CR-39 are presented with emphasis on the remarkable proton sensitivity of this new SSTR

  17. Portable radiation monitors

    International Nuclear Information System (INIS)

    Masui, Kaoru; Ishikura, Takeshi; Inui, Daisuke

    2007-01-01

    This paper presents an overview of typical portable radiation monitors and introduces Fuji Electric's latest models. The overview describes the types, uses and performance of ion chamber survey meters, GM survey meters and neutron ambient dose equivalent rate meters. Fuji Electric's new model of a wide-energy-range X/gamma ray survey meter which measures low energy X-rays up to 8 keV, a battery-powered environmental dosemeter system which measures dose history and is capable of continuous measurement with batteries over a year, and a portable monitoring post which measures dose rates from background to 10 8 nGy/h and transmits data by cellular phone are introduced, and their specifications and performance are described. (author)

  18. Radiation monitor reporting requirements

    International Nuclear Information System (INIS)

    Bates, W.F.

    1993-01-01

    Within High-Level Waste Management (HLWM), CAMs and VAMPs are currently considered Class B equipment, therefore, alarm conditions associated with the CAMs and VAMPs result in an Unusual Occurrence or Off-Normal notification and subsequent occurrence reporting. Recent equipment difficulties associated with Continuous Air Monitors (CAMs) and Victoreen Area Radiation Monitors (VAMPs) have resulted in a significant number of notification reports. These notification have the potential to decrease operator sensitivity to the significance of specific CAM and VAMP failures. Additionally, the reports are extremely costly and are not appropriate as a means for tracking and trending equipment performance. This report provides a technical basis for a change in Waste Management occurrence reporting categorization for specific CAM and VAMP failure modes

  19. Community Radiation Monitoring Program

    International Nuclear Information System (INIS)

    Cooper, E.N.

    1993-05-01

    The Community Radiation Monitoring Program (CRMP) is a cooperative effort between the US Department of Energy (DOE); the US Environmental Protection Agency (EPA); the Desert Research Institute (DRI), a division of the University and Community College System of Nevada and the Nuclear Engineering Laboratory of the University of Utah (UNEL). The twelfth year of the program began in the fall of 1991, and the work continues as an integral part of the DOE-sponsored long-term offsite radiological monitoring effort that has been conducted by EPA and its predecessors since the inception of nuclear testing at the Nevada Test Site (NTS). The program began as an outgrowth of activities that occurred during the Three Mile Island incident in 1979. The local interest and public participation that took place there were thought to be transferrable to the situation at the NTS, so, with adaptations, that methodology was implemented for this program. The CRMP began by enhancing and centralizing environmental monitoring and sampling equipment at 15 communities in the existing EPA monitoring network, and has since expanded to 19 locations in Nevada, Utah and California. The primary objectives of this program are still to increase the understanding by the people who live in the area surrounding the NTS of the activities for which DOE is responsible, to enhance the performance of radiological sampling and monitoring, and to inform all concerned of the results of these efforts. One of the primary methods used to improve the communication link with people in the potentially impacted area has been the hiring and training of local citizens as station managers and program representatives in those selected communities in the offsite area. These managers, active science teachers wherever possible, have succeeded, through their training, experience, community standing, and effort, in becoming a very visible, able and valuable asset in this link

  20. Radiation damage in optical fibers

    International Nuclear Information System (INIS)

    Lyons, P.B.; Looney, L.D.; Ogle, J.W.

    1983-01-01

    Optical fibers provide important advantages over coaxial cables for many data transmission applications. Some of these applications require that the fibers transmit data during a radiation pulse. Other applications utilize the fiber as a radiation-to-light transducer. In either case, radiation-induced luminescence and absorption must be understood. Most studies of radiation effects in fibers have emphasized time scales of interest in telecommunication systems, from the msec to hour range. Few studies have concentrated on response at times below 1 + s. At Los Alamos, both laboratory electron accelerators and nuclear tests have been used as radiation sources to probe this early time region. The use of a fiber (or any optical medium) as a Cerenkov radiation-to-light transducer is discussed. Since the radiation induces attenuation in the medium, the light output is not proportional to the radiation input. The nonlinearity introduced by this attenuation is calculated

  1. Programmed cellular response to ionizing radiation damage

    International Nuclear Information System (INIS)

    Crompton, N.E.A.

    1998-01-01

    Three forms of radiation response were investigated to evaluate the hypothesis that cellular radiation response is the result of active molecular signaling and not simply a passive physicochemical process. The decision whether or not a cell should respond to radiation-induced damage either by induction of rescue systems, e.g. mobilization of repair proteins, or induction of suicide mechanisms, e.g. programmed cell death, appears to be the expression of intricate cellular biochemistry. A cell must recognize damage in its genetic material and then activate the appropriate responses. Cell type is important; the response of a fibroblast to radiation damage is both quantitatively and qualitatively different form that of a lymphocyte. The programmed component of radiation response is significant in radiation oncology and predicted to create unique opportunities for enhanced treatment success. (orig.)

  2. Radiation damage in barium fluoride detector materials

    International Nuclear Information System (INIS)

    Levey, P.W.; Kierstead, J.A.; Woody, C.L.

    1988-01-01

    To develop radiation hard detectors, particularly for high energy physics studies, radiation damage is being studied in BaF 2 , both undoped and doped with La, Ce, Nd, Eu, Gd and Tm. Some dopants reduce radiation damage. In La doped BaF 2 they reduce the unwanted long lifetime luminescence which interferes with the short-lived fluorescence used to detect particles. Radiation induced coloring is being studied with facilities for making optical measurements before, during and after irradiation with 60 C0 gamma rays. Doses of 10 6 rad, or less, create only ionization induced charge transfer effects since lattice atom displacement damage is negligible at these doses. All crystals studied exhibit color center formation, between approximately 200 and 800 nm, during irradiation and color center decay after irradiation. Thus only measurements made during irradiation show the total absorption present in a radiation field. Both undoped and La doped BaF 2 develop damage at minimum detectable levels in the UV---which is important for particle detectors. For particle detector applications these studies must be extended to high dose irradiations with particles energetic enough to cause lattice atom displacement damage. In principle, the reduction in damage provided by dopants could apply to other applications requiring radiation damage resistant materials

  3. 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

  4. Radiation damage analysis by positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Siegel, R.W.

    1979-01-01

    The application of positron annihilation spectroscopy (PAS) to the characterization and study of defects in metals produced by radiation damage is discussed. The physical basis for the positron annihilation techniques (lifetime, Doppler broadening, angular correlation) is introduced and the techniques briefly described. Some examples of the application of PAS to radiation damage analysis are presented with a view toward elucidating the particular advantages of PAS over more traditional defect characterization techniques

  5. DNA Damage Signals and Space Radiation Risk

    Science.gov (United States)

    Cucinotta, Francis A.

    2011-01-01

    Space radiation is comprised of high-energy and charge (HZE) nuclei and protons. The initial DNA damage from HZE nuclei is qualitatively different from X-rays or gamma rays due to the clustering of damage sites which increases their complexity. Clustering of DNA damage occurs on several scales. First there is clustering of single strand breaks (SSB), double strand breaks (DSB), and base damage within a few to several hundred base pairs (bp). A second form of damage clustering occurs on the scale of a few kbp where several DSB?s may be induced by single HZE nuclei. These forms of damage clusters do not occur at low to moderate doses of X-rays or gamma rays thus presenting new challenges to DNA repair systems. We review current knowledge of differences that occur in DNA repair pathways for different types of radiation and possible relationships to mutations, chromosomal aberrations and cancer risks.

  6. Atmospheric radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.A. Leigui de; Peixoto, C.J. Todero; Leao, M.S.A.B.; Luzio, V.P. [Universidade Federal do ABC (UFABC), SP (Brazil); Barbosa, A.F.; Lima Junior, H.P.; Vilar, A.B.; Gama, R.G.; Ferraz, V.A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The Atmospheric Radiation Monitor (MonRAt) is a compact telescope designed to detect fluorescence photons generated in the atmosphere by ultra-high energy cosmic rays showers with energies in the interval between 10{sup 17} eV and 10{sup 18} eV. It is composite by a 64 pixels MultiAnodic PhotoMultiplier Tube (MAPMT) placed at the focus of a parabolic mirror mounted in a Newtonian telescope setup and the data acquisition system. In front of the MAPMT photocathode, filters will be positioned to select light with wavelength in the near ultraviolet region (300 nm < {lambda} < 450 nm) where the nitrogen fluorescent emissions occurs. The data acquisition system consists of a set of pre-amplifiers and FPGA-based boards able to record trigger times and waveforms from each channel and send the data to a computer by USB ports. MonRAt will be used to detect fluorescence photons under different atmospheric conditions (pressure, temperature, humidity, local geomagnetic field, etc) and will contribute with a detailed study of the fluorescence radiation yield. The assembly of the telescope is under way and we present in this work the status of the experiment and its first measurements in the laboratory. (author)

  7. Atmospheric radiation monitor

    International Nuclear Information System (INIS)

    Oliveira, M.A. Leigui de; Peixoto, C.J. Todero; Leao, M.S.A.B.; Luzio, V.P.; Barbosa, A.F.; Lima Junior, H.P.; Vilar, A.B.; Gama, R.G.; Ferraz, V.A.

    2011-01-01

    Full text: The Atmospheric Radiation Monitor (MonRAt) is a compact telescope designed to detect fluorescence photons generated in the atmosphere by ultra-high energy cosmic rays showers with energies in the interval between 10 17 eV and 10 18 eV. It is composite by a 64 pixels MultiAnodic PhotoMultiplier Tube (MAPMT) placed at the focus of a parabolic mirror mounted in a Newtonian telescope setup and the data acquisition system. In front of the MAPMT photocathode, filters will be positioned to select light with wavelength in the near ultraviolet region (300 nm < λ < 450 nm) where the nitrogen fluorescent emissions occurs. The data acquisition system consists of a set of pre-amplifiers and FPGA-based boards able to record trigger times and waveforms from each channel and send the data to a computer by USB ports. MonRAt will be used to detect fluorescence photons under different atmospheric conditions (pressure, temperature, humidity, local geomagnetic field, etc) and will contribute with a detailed study of the fluorescence radiation yield. The assembly of the telescope is under way and we present in this work the status of the experiment and its first measurements in the laboratory. (author)

  8. ERMS - Environmental Radiation Monitoring System

    International Nuclear Information System (INIS)

    Vax, Eran; Sarusi, Benny; Sheinfeld, Mati; Levinson, Shmuel; Brandys, Irad; Sattinger, Danny; Wengrowicz, Udi; Tshuva, Avi; Tirosh, Dan

    2008-01-01

    A new Environmental Radiation Monitoring System (ERMS) has been developed in the NRCN as an extensive tool to be applied in case of nuclear malfunction or Nuclear Disposal Device (NDD) incident, as well as for routine radiation monitoring of the reactor's vicinity. The system collects real-time environmental data such as: gamma radiation, wind speed, wind direction, and temperature for monitoring purposes. The ERMS consists of a main Control Center and an array of monitoring stations. Fixed, environmental, gamma radiation monitoring stations are installed at the reactor's surroundings while portable stations can be posted rapidly along the wind direction, enhancing the spatial sampling of the radiation measurements and providing better hazard assessment at an emergency event. The presented ERMS, based on industrial standards for hardware and network protocols, is a reliable standalone system which upgrades the readiness to face a nuclear emergency event by supplying real-time, integrated meteorological and radiation data. (author)

  9. Radiation damage of metal uranium

    International Nuclear Information System (INIS)

    Mihajlovic, A.

    1965-01-01

    This report is concerned with the role of dispersion second phase in uranium and burnup rate. The role of dispersion phases in radiation stability of metal uranium was studies by three methods: variation of electric conductivity dependent on the neutron flux and temperature of pure uranium for different states of dispersion second phase; influence of dispersion phase on the radiation creep; transmission electron microscopy of fresh and irradiated uranium

  10. Air and radiation monitoring stations

    CERN Multimedia

    AUTHOR|(SzGeCERN)582709

    2015-01-01

    CERN has around 100 monitoring stations on and around its sites. New radiation measuring stations, capable of detecting even lower levels of radiation, were installed in 2014. Two members of HE-SEE group (Safety Engineering and Environment group) in front of one of the new monitoring stations.

  11. Molecular mechanisms in radiation damage to DNA

    International Nuclear Information System (INIS)

    Osman, R.

    1991-01-01

    The objectives of this work are to elucidate the molecular mechanisms that are responsible for radiation-induced DNA damage. The overall goal is to understand the relationship between the chemical and structural changes produced by ionizing radiation in DNA and the resulting impairment of biological function expressed as carcinogenesis or cell death. The studies are based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA. These mechanistic explorations should lead to the formulation of testable hypothesis regarding the processes of impairment of regulation of gene expression, alternation in DNA repair, and damage to DNA structure involved in cell death or cancer

  12. New concepts for radiation damage

    International Nuclear Information System (INIS)

    Michelin, Severino C.

    2004-01-01

    Evidence accumulated over the past two decades has indicated that exposure of cell populations to ionizing radiation results in significant biological effects occurring in both the irradiated and non-irradiated cells in the population. This phenomenon, termed the 'bystander response', has been shown to occur both in vitro and in vivo. Experiments have indicated that genetic alterations, changes in gene expression and lethality occur in bystander cells that neighbour directly irradiated cells. Furthermore, cells recipient of growth medium harvested from irradiated cultures exhibit responses similar to those of the irradiated cells. Several mechanisms involving secreted soluble factors, gap-junction intercellular communication and oxidative metabolism have been proposed to regulate the radiation-induced bystander effect. In this lecture, our current knowledge of this phenomenon and its potential impact both on the estimation of risks of exposure to low doses/low fluences of ionizing radiation and on radiotherapy is discussed. (author)

  13. Analysis of radiation damaged nanocrystals

    International Nuclear Information System (INIS)

    Sitek, J.; Dekan, J.; Sedlackova, K.; Sagatova, A.

    2014-01-01

    Ribbon-shaped specimens of the master alloy were prepared by planar flow casting. The ribbons with nominal composition of (Fe_1_-_xN_x)_8_1Nb_7B_1_2 (x = 0, 0.25, 0.5, 0.75) were about 25 μm thick and 10 mm wide. To achieve nanocrystalline state, the amorphous ribbons were annealed in vacuum at the temperature of 550 grad C for 1 hour. Samples were irradiated by neutrons in nuclear reactor with fluence of 10"1"6 n/cm"2 and 10"1"7 n/cm"2. and by electrons in linear accelerator with dose 1 MGy at the Slovak Medical University. Moessbauer spectra were collected in transmission geometry by a conventional constant-acceleration spectrometer with a "5"7Co(Rh) source. All spectra were measured at room temperature and evaluated by the CONFIT program, which allows simultaneous treatment of crystalline and residual amorphous phase by means of individual lines and distribution of hyperfine components. After summarizing all obtained results, the fluence 10"1"6 n/cm"2 is still not sufficiently high significantly damage amorphous and crystalline structure. This fluence more or less modify the structure than damage. After fluence 10"17"n/cm"2 we observed beginning of the. structural damage. Our results show, that high electron dose also modify the structure of nanocrystaline alloys. In further study of this alloy it would be necessary to find the limit of electron dose under that the alloy is resistant against electron's damage. From point of view Moessbauer spectroscopy the most sensitive parameter is direction of net magnetic moment. (authors)

  14. USB-based radiation monitor

    International Nuclear Information System (INIS)

    Drndarevic, V.; Jevtic, N.; Djuric, R.

    2006-01-01

    The Universal Serial Bus has become a dominant interface for the connection of standard peripheral devices to a personal computer. This paper analyzes the possibilities of USB bus applications in the field of measurement and environmental monitoring. As a result, a gamma radiation monitor consisting of an USB-based universal peripheral device and a gamma probe with a GM counter, has been designed. For the interfacing monitor with the powerful and easy to use LabVIEW software package, an instrument driver as a set of virtual instruments has been developed. The proposed monitor is a flexible instrument which can be used for laboratory measurements, as an environmental radiation monitor or for training purposes. Connected to the laptop computer, the monitor becomes a portable instrument suitable for field measurements. Basic measurements and functionality properties of the radiation monitor are presented here

  15. Mechanisms for radiation damage in DNA

    International Nuclear Information System (INIS)

    Sevilla, M.D.

    1993-12-01

    In this project the author has proposed several mechanisms for radiation damage to DNA and its constituents, and has detailed a series of experiments utilizing electron spin resonance spectroscopy, HPLC, GC-mass spectroscopy and ab initio molecular orbital calculations to test the proposed mechanisms. In this years work he has completed several experiments on the role of hydration water on DNA radiation damage, continued the investigation of the localization of the initial charges and their reactions on DNA, investigated protonation reactions in DNA base anions, and employed ab initio molecular orbital theory to gain insight into the initial events of radiation damage to DNA. Ab initio calculations have provided an understanding of the energetics evolved in anion and cation formation, ion radical transfer in DNA as well as proton transfer with DNA base pair radical ions. This has been extended in this years work to a consideration of ionization energies of various components of the DNA deoxyribose backbone and resulting neutral sugar radicals. This information has aided the formation of new radiation models for the effect of radiation on DNA. During this fiscal year four articles have been published, four are in press, one is submitted and several more are in preparation. Four papers have been presented at scientific meetings. This years effort will include another review article on the open-quotes Electron Spin Resonance of Radiation Damage to DNAclose quotes

  16. Advances in radiation protection monitoring

    International Nuclear Information System (INIS)

    1978-01-01

    The requirement to keep radiation exposure as low as reasonably achievable, linked with the growing number of workers whose exposure to radiation must be strictly controlled, requires intensified efforts directed towards the provision of adequate radiation monitoring programmes. This symposium was intended to review the advances that have been made in methods, techniques and instrumentation for radiation protection monitoring. Thus the symposium complemented the detailed consideration that had already been given to two closely related topics, that of environmental monitoring and of monitoring radioactive airborne and liquid discharges from nuclear facilities. The first topic had been dealt with in detail in an Agency symposium held in November 1973 in Warsaw and the second was treated in an Agency symposium held in September 1977 in Portoroz. The present symposium covered a broad range of topics under the following main headings: Monitoring of external exposure (three sessions),Contamination monitoring (three sessions), Radiation monitoring programmes (one session), Calibration, and use of computers (two sessions). An introductory paper described the purpose of radiation protection monitoring and its historical development. It drew attention to the gradual change from the threshold dose hypothesis to the hypothesis of direct proportionality between dose and effect and discussed practical implications of the recommendations recently issued by the International Commission on Radiological Protection (ICRP). It became apparent that guidance on the application of these recommendations is urgently needed. This guidance is presently being prepared by ICRP

  17. Maintenance of radiation monitoring systems

    International Nuclear Information System (INIS)

    Aoyama, Kei

    2001-01-01

    As the safety and quality of atomic power facilities are more strongly required, the reliability improvement and preventive maintenance of radiation monitoring systems are important. This paper describes the maintenance of radiation monitoring systems delivered by Fuji Electric and the present status of preventive maintenance technology. Also it introduces the case that we developed a fault diagnosis function adopting a statistics technique and artificial intelligence (AI) and delivered a radiation monitoring system including this function. This system can output a fault analysis result and a countermeasure from the computer in real time. (author)

  18. Nanofoams Response to Radiation Damage

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Engang [Los Alamos National Laboratory; Serrano De Caro, Magdalena [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory; Nastasi, Michael [Nebraska Center for Energy Sciences Research, University of Nebraska-Lincoln, NE 68508; Zepeda-Ruiz, Luis [PLS, Lawrence Livermore National Laboratory, Livermore, CA 94551; Bringa, Eduardo M. [CONICET and Inst. Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza, 5500 Argentina; Baldwin, Jon K. [Los Alamos National Laboratory; Caro, Jose A. [Los Alamos National Laboratory

    2012-07-30

    Conclusions of this presentation are: (1) np-Au foams were successfully synthesized by de-alloying process; (2) np-Au foams remain porous structure after Ne ion irradiation to 1 dpa; (3) SFTs were observed in irradiated np-Au foams with highest and intermediate flux, while no SFTs were observed with lowest flux; (4) SFTs were observed in irradiated np-Au foams at RT, whereas no SFTs were observed at LNT irradiation; (5) The diffusivity of vacancies in Au at RT is high enough so that the vacancies have enough time to agglomerate and thus collapse. As a result, SFTs were formed; (6) The high flux created much more damage/time, vacancies don't have enough time to diffuse or recombine. As a result, SFTs were formed.

  19. Tooth-germ damage by ionizing radiation

    International Nuclear Information System (INIS)

    Sobkowiak, E.M.; Beetke, E.; Bienengraeber, V.; Held, M.; Kittner, K.H.

    1977-01-01

    Experiments on animals (four-week-old dogs) were conducted in an investigation made to study the possibility of dose-dependent tooth-germ damage produced by ionizing radiation. The individual doses were 50 R and 200 R, respectively, and they were administered once to three times at weekly intervals. Hyperemia and edemata could be observed on tooth-germ pulps from 150 R onward. Both of these conditions became more acute as the radiation dose increased (from 150 R to 600 R). Possible damage to both the dentin and enamel is pointed out. (author)

  20. Radiation damage in organic materials

    International Nuclear Information System (INIS)

    Campbell, F.J.

    1981-01-01

    A surprising number of electrical components and seals are listed as being inside the containment building of a nuclear power plant. The types of radiation and their interaction with organic materials lead to a dosimetry discussion, and then a brief description of the chemical mechanisms which predominate in typical organic materials follows. Relative stability of polymer structures and the types of additives that contribute stabilization to the basic polymer matrix in formulated compounds are reviewed. However, the emphasis must now be directed toward the need to consider the total environment of nuclear plant service on the degradation of these materials if maximum reliability is to be achieved. The degradation mechanisms may be strongly affected by the dose-rate/oxidation effect. Temperature, steam and physical stress, when applied concurrently with the radiation field, can also influence the amount of absorbed dose required to produce a given change in the property being tested. Determining the degree of these influences and developing standardized test procedures to evaluate them have become the objective of several prominent research programs and international committee efforts. (author)

  1. Radiation damage to electronic components

    International Nuclear Information System (INIS)

    Battisti, S.; Bossart, R.; Schoenbacher, H.; Van de Voorde, M.

    1975-01-01

    Characteristic properties are presented of some 40 different electronic components (resistors, capacitors, diodes, transistors, and integrated circuits) which were irradiated in a nuclear reactor up to 1015 n/cm 2 (E > 1 MeV). Complete circuits (e.g. RF amplifiers and detectors, mixers, differential amplifiers, voltage-to-frequency converters, oscillators, power supplies) were irradiated near the CERN Intersecting Storage Rings up to 106 rad(RPL) (dose measured with radiophotoluminescent dosimeters) under simulated operational conditions. Representative measured parameters, such as resistance, capacitance, forward voltage, reverse current, toggle frequencies, are given in graphs as a function of radiation dose. The results are discussed in detail and lead to the over-all conclusion that the operation of electronic components and circuits is seriously affected by radiation environments with doses in the order of 10 13 n/cm 2 or 10 4 rad(RPL); some components and circuits fail completely at doses of 10 14 n/cm 2 or 10 5 rad(RPL). (Author)

  2. Mechanisms for radiation damage in DNA

    International Nuclear Information System (INIS)

    Sevilla, M.D.

    1985-07-01

    Radiation damage to DNA results from the direct interaction of radiation with DNA where positive ions, electrons and excited states are formed in the DNA, and the indirect effect where radical species formed in the surrounding medium by the radiation attack the DNA. The primary mechanism proposed for radiation damage, by the direct effect, is that positive and negative ions formed within the DNA strand migrate through the stacked DNA bases. The ions can then recombine, react with the DNA bases most likely to react by protonation of the anion and deprotonation or hydroxylation of the cation or transfer out of the DNA chain to the surrounding histone protein. This work as aimed at understanding the possible reactions of the DNA base ion radicals, as well as their initial distribution in the DNA strand. 31 refs

  3. Size effect in radiation damage

    International Nuclear Information System (INIS)

    Brumovsky, M.

    1979-01-01

    Radiation embrittlement of nuclear reactor pressure vessel steels is mostly measured using small standard specimens in dynamic bend tests. Their dimensions are much smaller than those of the reactor. The increase in the critical temperature (transition temperature from the brittle-to-ductile fracture) is normally measured using standard Charpy-V type specimens or small CT-type specimens. This increase is then used as the main parameter for the pressure vessel safety evaluation. The philosophy of experiments is discussed used for the nonirradiated and irradiated pressure vessel steels. A comparison of the increase in the transition temperature measured in different types of specimens using various testing methods (static and dynamic bend tests with notch or crack) is also made. The results of this comparison and another study showed a relatively good agreement. (author)

  4. Radiation induced genetic damage in Aspergillus nidulans

    International Nuclear Information System (INIS)

    Georgiou, J.T.

    1984-01-01

    The mechanism by which ionizing radiation induces genetic damage in haploid and diploid conidia of Aspergillus nidulans was investigated. Although the linear dose-response curves obtained following low LET irradiation implied a 'single-hit' action of radiation, high LET radiations were much more efficient than low LET radiations, which suggests the involvement of a multiple target system. It was found that the RBE values for non-disjunction and mitotic crossing-over were very different. Unlike mitotic crossing-over, the RBE values for non-disjunction were much greater than for cell killing. This suggests that non-disjunction is a particularly sensitive genetical endpoint that is brought about by damage to a small, probably non-DNA target. Radiosensitisers were used to study whether radiation acts at the level of the DNA or some other cellular component. The sensitisation to electrons and/or X-rays by oxygen, and two nitroimidazoles (metronidazole and misonidazole) was examined for radiation induced non-disjunction, mitotic crossing-over, gene conversion, point mutation and cell killing. It was found that these compounds sensitised the cells considerably more to genetic damage than to cell killing. (author)

  5. Measurement of radiation damage on an epoxy-based optical glue

    International Nuclear Information System (INIS)

    Huang, H.C.; Peng, K.C.; Sahu, S.K.; Ueno, K.; Chang, Y.H.; Wang, C.H.; Hou, W.S.

    1997-01-01

    We measured the radiation damage on an optical glue called Eccobond-24, which is a candidate for CsI and BGO crystal calorimeters of the BELLE detector of the KEK B-factory. Absorption spectrophotometry in the range 300-800 nm was used to monitor the radiation damage. The maximum equivalent dose was 1.64 Mrad. The glue shows effects of damage, but is acceptable for the radiation level in the above-mentioned experiment. (orig.)

  6. Practical radiation monitoring

    International Nuclear Information System (INIS)

    Keightley, Lynsey; Burgess, Peter; Delahunty, Denise; Richards, Tony; Simpson, John; Woods, Mike

    2002-01-01

    This Good Practice Guide has been written by a working party of experts from the UK Ionising Radiation Metrology Forum. It describes procedures and methods for assessing radiation levels, outlines the thought processes needed to carry out the measurements and gives practical advice. The methods described are general and based on currently accepted good practice

  7. Radiation damage effect on avalanche photodiodes

    CERN Document Server

    Baccaro, S; Cavallari, F; Da Ponte, V; Deiters, K; Denes, P; Diemoz, M; Kirn, Th; Lintern, A L; Longo, E; Montecchi, M; Musienko, Y; Pansart, J P; Renker, D; Reucroft, S; Rosi, G; Rusack, R; Ruuska, D; Stephenson, R; Torbet, M J

    1999-01-01

    Avalanche Photodiodes have been chosen as photon sensors for the electromagnetic calorimeter of the CMS experiment at the LHC. These sensors should operate in the 4T magnetic field of the experiment. Because of the high neutron radiation in the detector extensive studies have been done by the CMS collaboration on the APD neutron radiation damage. The characteristics of these devices after irradiation have been analized, with particular attention to the quantum efficiency and the dark current. The recovery of the radiation induced dark current has been studied carefully at room temperature and at slightly lower and higher temperatures. The temperature dependence of the defects decay-time has been evaluated.

  8. Mechanisms for radiation damage in DNA

    International Nuclear Information System (INIS)

    Sevilla, M.D.

    1987-01-01

    Several mechanisms are proposed for radiation damage to DNA and its constituents, and a series of experiments utilizing electron spin resonance spectrometry have been used to test the proposed mechanisms. In the past we have concentrated chiefly on investigating irradiated systems of DNA constituents. In this year's effort we have concentrated on radiation effects on DNA itself. In addition studies of radiation effects on lipids and model compounds have been performed which shed light on the only other proposed site for cell kill, the membrane

  9. The Status of Radiation Damage Experiments

    International Nuclear Information System (INIS)

    Strachan, Denis M.; Scheele, Randall D.; Icenhower, Jonathan P.; Kozelisky, Anne E.; Sell, Richard L.; Legore, Virginia L.; Schaef, Herbert T.; O'Hara, Matthew J.; Brown, Christopher F.; Buchmiller, William C.

    2001-01-01

    Experiments have been on-going for about two years to determine the effects that radiation damage have on the physical and chemical properties of candidate titanate ceramics for the immobilization of plutonium. We summarize the results of these experiments in this document

  10. Radiation damage of polymers in ultrasonic fields

    Energy Technology Data Exchange (ETDEWEB)

    Anbalagan, Poornnima

    2008-07-01

    Radiation damage has always been a topic of great interest in various fields of sciences. In this work, an attempt is made to probe into the effect of subthreshold ultrasonic waves on the radiation damage created by irradiation of deuterons in polymer samples wherein the polymer samples act as model systems. Two equal volumes of radiation damage were produced in a single polymer sample wherein a standing wave of ultrasound was introduced into one. Three polymers namely, Polycarbonate, Polymethylmethacrylate and Polyvinyl chloride were used in this work. Four independent techniques were used to analyze the irradiated samples and visualize the radiation damage. Interferometric measurements give a measure of the refractive index modulation in the irradiated sample. Polymers, being transparent, do not absorb in the visible region of the electromagnetic spectrum. UV-Vis absorption spectroscopy shows absorption peaks in the visible region in irradiated polymer samples. Ion irradiation causes coloration of polymers. The light microscope is used to measure the absorption of white light by the irradiated polymers. Positron annihilation spectroscopy is used to obtain a measure of the open volume created by irradiation in polymers. A comparison between the irradiated region and the region exposed to ultrasonic waves simultaneously with irradiation in a polymer sample shows the polymer specific influence of the ultrasonic standing wave. (orig.)

  11. Radiation damage of polymers in ultrasonic fields

    International Nuclear Information System (INIS)

    Anbalagan, Poornnima

    2008-01-01

    Radiation damage has always been a topic of great interest in various fields of sciences. In this work, an attempt is made to probe into the effect of subthreshold ultrasonic waves on the radiation damage created by irradiation of deuterons in polymer samples wherein the polymer samples act as model systems. Two equal volumes of radiation damage were produced in a single polymer sample wherein a standing wave of ultrasound was introduced into one. Three polymers namely, Polycarbonate, Polymethylmethacrylate and Polyvinyl chloride were used in this work. Four independent techniques were used to analyze the irradiated samples and visualize the radiation damage. Interferometric measurements give a measure of the refractive index modulation in the irradiated sample. Polymers, being transparent, do not absorb in the visible region of the electromagnetic spectrum. UV-Vis absorption spectroscopy shows absorption peaks in the visible region in irradiated polymer samples. Ion irradiation causes coloration of polymers. The light microscope is used to measure the absorption of white light by the irradiated polymers. Positron annihilation spectroscopy is used to obtain a measure of the open volume created by irradiation in polymers. A comparison between the irradiated region and the region exposed to ultrasonic waves simultaneously with irradiation in a polymer sample shows the polymer specific influence of the ultrasonic standing wave. (orig.)

  12. Acoustic emission sensor radiation damage threshold experiment

    International Nuclear Information System (INIS)

    Beeson, K.M.; Pepper, C.E.

    1994-01-01

    Determination of the threshold for damage to acoustic emission sensors exposed to radiation is important in their application to leak detection in radioactive waste transport and storage. Proper response to system leaks is necessary to ensure the safe operation of these systems. A radiation impaired sensor could provide ''false negative or false positive'' indication of acoustic signals from leaks within the system. Research was carried out in the Radiochemical Technology Division at Oak Ridge National Laboratory to determine the beta/gamma radiation damage threshold for acoustic emission sensor systems. The individual system consisted of an acoustic sensor mounted with a two part epoxy onto a stainless steel waveguide. The systems were placed in an irradiation fixture and exposed to a Cobalt-60 source. After each irradiation, the sensors were recalibrated by Physical Acoustics Corporation. The results were compared to the initial calibrations performed prior to irradiation and a control group, not exposed to radiation, was used to validate the results. This experiment determines the radiation damage threshold of each acoustic sensor system and verifies its life expectancy, usefulness and reliability for many applications in radioactive environments

  13. Study of radiation damage in metals by positron annihilation

    International Nuclear Information System (INIS)

    Gauster, W.B.

    1977-01-01

    Positron annihilation is a sensitive technique for probing defects in metals and it has recently been shown to be a valuable tool for the study of radiation damage. After an introduction to the three basic experimental methods (angular correlation, Doppler broadening, and lifetime measurements), the interaction of positrons with lattice defects is reviewed. Results for the annealing of damage after low temperature irradiation are used to show that positron annihilation has provided new information on annealing kinetics. The role of positron techniques in characterizing complex defect structures resulting from high-temperature neutron irradiation is reviewed and the possible utility of positron annihilation as a nondestructive monitor of property changes is pointed out

  14. Environmental radiation monitoring

    International Nuclear Information System (INIS)

    Lachmann, Markus

    2012-01-01

    The report includes the following chapters: Development of earth and cosmic radiation - natural radioactivity. Atomic weapon tests and medicine - artificial radioactivity. A disaster and its consequences. From the air to humans; lessons learned from Chernobyl - division of work during measurements. From potatoes to baby food - the routine measuring program. Preparedness for the case of emergency - the intensive program. Three question for Martin Riepenhausen.

  15. Radiation damage studies of nuclear structural materials

    International Nuclear Information System (INIS)

    Barat, P.

    2012-01-01

    Maximum utilization of fuel in nuclear reactors is one of the important aspects for operating them economically. The main hindrance to achieve this higher burnups of nuclear fuel for the nuclear reactors is the possibility of the failure of the metallic core components during their operation. Thus, the study of the cause of the possibility of failure of these metallic structural materials of nuclear reactors during full power operation due to radiation damage, suffered inside the reactor core, is an important field of studies bearing the basic to industrial scientific views.The variation of the microstructure of the metallic core components of the nuclear reactors due to radiation damage causes enormous variation in the structure and mechanical properties. A firm understanding of this variation of the mechanical properties with the variation of microstructure will serve as a guide for creating new, more radiation-tolerant materials. In our centre we have irradiated structural materials of Indian nuclear reactors by charged particles from accelerator to generate radiation damage and studied the some aspects of the variation of microstructure by X-ray diffraction studies. Results achieved in this regards, will be presented. (author)

  16. Radiation-damage calculations with NJOY

    International Nuclear Information System (INIS)

    MacFarlane, R.E.; Muir, D.W.; Mann, F.W.

    1983-01-01

    Atomic displacement, gas production, transmutation, and nuclear heating can all be calculated with the NJOY nuclear data processing system using evaluated data in ENDF/B format. Using NJOY helps assure consistency between damage cross sections and those used for transport, and NJOY provides convenient interface formats for linking data to application codes. Unique features of the damage calculation include a simple momentum balance treatment for radiative capture and a new model for (n, particle) reactions based on statistical model calculations. Sample results for iron and nickel are given and compared with the results of other methods

  17. Radiation damage in nanostructured metallic films

    Science.gov (United States)

    Yu, Kaiyuan

    High energy neutron and charged particle radiation cause microstructural and mechanical degradation in structural metals and alloys, such as phase segregation, void swelling, embrittlement and creep. Radiation induced damages typically limit nuclear materials to a lifetime of about 40 years. Next generation nuclear reactors require materials that can sustain over 60 - 80 years. Therefore it is of great significance to explore new materials with better radiation resistance, to design metals with favorable microstructures and to investigate their response to radiation. The goals of this thesis are to study the radiation responses of several nanostructured metallic thin film systems, including Ag/Ni multilayers, nanotwinned Ag and nanocrystalline Fe. Such systems obtain high volume fraction of boundaries, which are considered sinks to radiation induced defects. From the viewpoint of nanomechanics, it is of interest to investigate the plastic deformation mechanisms of nanostructured films, which typically show strong size dependence. By controlling the feature size (layer thickness, twin spacing and grain size), it is applicable to picture a deformation mechanism map which also provides prerequisite information for subsequent radiation hardening study. And from the viewpoint of radiation effects, it is of interest to explore the fundamentals of radiation response, to examine the microstructural and mechanical variations of irradiated nanometals and to enrich the design database. More importantly, with the assistance of in situ techniques, it is appealing to examine the defect generation, evolution, annihilation, absorption and interaction with internal interfaces (layer interfaces, twin boundaries and grain boundaries). Moreover, well-designed nanostructures can also verify the speculation that radiation induced defect density and hardening show clear size dependence. The focus of this thesis lies in the radiation response of Ag/Ni multilayers and nanotwinned Ag

  18. Radiation damage in nuclear waste materials

    International Nuclear Information System (INIS)

    Jencic, I.

    2000-01-01

    Final disposal of high-level radioactive nuclear waste is usually envisioned in some sort of ceramic material. The physical and chemical properties of host materials for nuclear waste can be altered by internal radiation and consequently their structural integrity can be jeopardized. Assessment of long-term performance of these ceramic materials is therefore vital for a safe and successful disposal. This paper presents an overview of studies on several possible candidate materials for immobilization of fission products and actinides, such as spinel (MgAl 2 O 4 ), perovskite (CaTiO 3 ), zircon (ZrSiO 4 ), and pyrochlore (Gd 2 Ti 2 O 7 and Gd 2 Zr 2 O 7 ). The basic microscopic picture of radiation damage in ceramics consists of atomic displacements and ionization. In many cases these processes result in amorphization (metaminctization) of irradiated material. The evolution of microscopic structure during irradiation leads to various macroscopic radiation effects. The connection between microscopic and macroscopic picture is in most cases at least qualitatively known and studies of radiation induced microscopic changes are therefore an essential step in the design of a reliable nuclear waste host material. The relevance of these technologically important results on our general understanding of radiation damage processes and on current research efforts in Slovenia is also addressed. (author)

  19. Nonuniform radiation damage in permanent magnet quadrupoles.

    Science.gov (United States)

    Danly, C R; Merrill, F E; Barlow, D; Mariam, F G

    2014-08-01

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

  20. Nonuniform radiation damage in permanent magnet quadrupoles

    International Nuclear Information System (INIS)

    Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G.

    2014-01-01

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components

  1. Nonuniform radiation damage in permanent magnet quadrupoles

    Energy Technology Data Exchange (ETDEWEB)

    Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    2014-08-15

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

  2. Radiation damage at LHCb, results and expectations

    CERN Multimedia

    Faerber, Christian

    2011-01-01

    The LHCb Detector is a single-arm spectrometer at the LHC designed to detect new physics through measuring CP violation and rare decays of heavy flavor mesons. The detector consists of vertex detector, tracking system, dipole magnet, 2 RICH detectors, em. calorimeter, hadron calorimeter, muon detector which all use different technologies and suffer differently from radiation damage. These radiation damage results and the investigation methods will be shown. The delivered luminosity till July 2011 was about 450 pb−1. The Vertex detector receives the highest particle flux at LHCb. The currents drawn by the silicon sensors are, as expected, increasing proportional to the integrated luminosity. The highest irradiaton regions of the n-bulk silicon sensors are observed to have recently undergone space charge sign inversion. The Silicon Trackers show increasing leakage currents comparable with earlier predictions. The electromagentic calorimeter and hadron calorimeter suffer under percent-level signal decrease whi...

  3. Radiation Damage in the LHCb VELO

    CERN Multimedia

    Harrison, Jon

    2011-01-01

    The VErtex LOcator (VELO) is a silicon strip detector designed to reconstruct particle tracks and vertices produced by proton-proton interactions near to the LHCb interaction point. The excellent track resolution and decay vertex separation provided by the VELO are essential to all LHCb analyses. For the integrated luminosity delivered by the LHC up to the end of $2011$ the VELO is exposed to higher particle fluences than any other silicon detector of the four major LHC experiments. These proceedings present results from radiation damage studies carried out during the first two years of data taking at the LHC. Radiation damage has been observed in all of the $88$ VELO silicon strip sensors, with many sensors showing evidence of type-inversion in the highest fluence regions. Particular attention has been given to the two \

  4. Radiation damage of uranium; Radijaciono ostecenje urana

    Energy Technology Data Exchange (ETDEWEB)

    Lazarevic, Dj [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1966-11-15

    Study of radiation damage covered the following: Kinetics of electric resistance of uranium and uranium alloy with 1% of molybdenum dependent on the second phase and burnup rate; Study of gas precipitation and diffusion of bubbles by transmission electron microscopy; Numerical analysis of the influence of defects distribution and concentration on the rare gas precipitation in uranium; study of thermal sedimentation of uranium alloy with molybdenum; diffusion of rare gas in metal by gas chromatography method.

  5. DNA damage caused by ionizing radiation

    International Nuclear Information System (INIS)

    Sachs, R.K.; Peili Chen; Hahnfeldt, P.J.; Klatky, L.R.

    1992-01-01

    A survey is given of continuous-time Markov chain models for ionizing radiation damage to the genome of mammalian cells. In such models, immediate damage induced by the radiation is regarded as a batch-Poisson arrival process of DNA double-strand breaks (DSBs). Enzymatic modification of the immediate damage is modeled as a Markov process similar to those described by the master equation of stochastic chemical kinetics. An illustrative example is the restitution/complete-exchange model. The model postulates that, after being induced by radiation, DSBs subsequently either undergo enzymatically mediated restitution (repair) or participate pairwise in chromosome exchanges. Some of the exchanges make irremediable lesions such as dicentric chromosome aberrations. One may have rapid irradiation followed by enzymatic DSB processing or have prolonged irradiation with both DSB arrival and enzymatic DSB processing continuing throughout the irradiation period. Methods for analyzing the Markov chains include using an approximate model for expected values, the discrete-time Markov chain embedded at transitions, partial differential equations for generating functions, normal perturbation theory, singular perturbation theory with scaling, numerical computations, and certain matrix methods that combine Perron-Frobenius theory with variational estimates. Applications to experimental results on expected values, variances, and statistical distributions of DNA lesions are briefly outlined. Continuous-time Markov chains are the most systematic of those radiation damage models that treat DSB-DSB interactions within the cell nucleus as homogeneous (e.g., ignore diffusion limitations). They contain virtually all other relevant homogeneous models and semiempirical summaries as special cases, limiting cases, or approximations. However, the Markov models do not seem to be well suited for studying spatial dependence of DSB interactions. 51 refs., 5 figs

  6. Mobile environmental radiation monitoring station

    International Nuclear Information System (INIS)

    Assido, H.; Shemesh, Y.; Mazor, T.; Tal, N.; Barak, D.

    1997-01-01

    A mobile environmental radiation monitoring station has been developed and established for the Israeli Ministry of Environment. The radiation monitoring station is ready for immediate placing in any required location, or can be operated from a vehicle. The station collects data Tom the detector and transfers it via cellular communication network to a Computerized Control Center for data storage, processing, and display . The mobile station is fully controlled from the. Routinely, the mobile station responses to the data request accumulated since the last communication session. In case of fault or alarm condition in the mobile station, a local claim is activated and immediately initiates communication with the via cellular communication network. (authors)

  7. Pathology of radiation induced lung damage

    International Nuclear Information System (INIS)

    Kawabata, Yoshinori; Murata, Yoshihiko; Ogata, Hideo; Katagiri, Shiro; Sugita, Hironobu; Iwai, Kazuo; Sakurai, Isamu.

    1985-01-01

    We examined pathological findings of radiation induced lung damage. Twenty-three cases are chosen from our hospital autopsy cases for 9 years, which fulfil strict criteria of radiation lung damage. Lung damage could be classified into 3 groups : 1) interstitial pneumonia type (9 cases), 2) intermediate pneumonia type (8 cases), and 3) alveolar pneumonia type (6 cases), according to the degree of intra-luminal exudation. These classification is well correlated with clinical findings. Pathological alveolar pneumonia type corresponds to symptomatic, radiologic ground glass pneumonic shadow. And pathologic interstitial type corresponds to clinical asymptomatic, radiologic reticulo-nodular shadow. From the clinico-pathological view point these classification is reasonable one. Radiation affects many lung structures and showed characteristic feature of repair. Elastofibrosis of the alveolar wall is observed in every cases, obstructive bronchiolitis are observed in 5 cases, and obstructive bronchiolitis in 9 cases. They are remarkable additional findings. Thickening of the interlobular septum, broncho-vascular connective tissue, and pleural layer are observed in every cases together with vascular lesions. (author)

  8. Radiation detectors as surveillance monitors

    International Nuclear Information System (INIS)

    Fehlau, P.E.; Dowdy, E.J.

    1981-01-01

    The International Atomic Energy Agency (IAEA) proposes to use personnel dosimetry radiation detectors as surveillance monitors for safeguards purposes. It plans to place these YES/NO monitors at barrier penetration points declared closed under IAEA safeguards to detect the passage of plutonium-bearing nuclear material, usually spent fuel. For this application, commercially available dosimeters were surveyed as well as other radiation detectors that appeared suitable and likely to be marketed in the near future. No primary advantage was found in a particular detector type because in this application backgrounds vary during long counting intervals. Secondary considerations specify that the monitor be inexpensive and easy to tamper-proof, interrogate, and maintain. On this basis radiophotoluminescent, thermoluminescent, and electronic dosimeters were selected as possible routine monitors; the latter two may prove useful for data-base acquisition

  9. Chromatin damage induced by fast neutrons or UV laser radiation

    Energy Technology Data Exchange (ETDEWEB)

    Radu, L.; Constantinescu, B.; Gazdaru, D.; Mihailescu, I

    2002-07-01

    Chromatin samples from livers of Wistar rats were subjected to fast neutron irradiation in doses of 10-100 Gy or to a 248 nm excimer laser radiation, in doses of 0.5-3 MJ.m{sup -2}. The action of the radiation on chromatin was monitored by chromatin intrinsic fluorescence and fluorescence lifetimes (of bound ethidium bromide to chromatin) and by analysing fluorescence resonance energy transfer between dansyl chloride and acridine orange coupled to chromatin. For the mentioned doses of UV excimer laser radiation, the action on chromatin was more intense than in the case of fast neutrons. The same types of damage are produced by the two radiations: acidic and basic destruction of chromatin protein structure, DNA strand breaking and the increase of the distance between DNA and proteins in chromatin. (author)

  10. Chromatin damage induced by fast neutrons or UV laser radiation

    International Nuclear Information System (INIS)

    Radu, L.; Constantinescu, B.; Gazdaru, D.; Mihailescu, I.

    2002-01-01

    Chromatin samples from livers of Wistar rats were subjected to fast neutron irradiation in doses of 10-100 Gy or to a 248 nm excimer laser radiation, in doses of 0.5-3 MJ.m -2 . The action of the radiation on chromatin was monitored by chromatin intrinsic fluorescence and fluorescence lifetimes (of bound ethidium bromide to chromatin) and by analysing fluorescence resonance energy transfer between dansyl chloride and acridine orange coupled to chromatin. For the mentioned doses of UV excimer laser radiation, the action on chromatin was more intense than in the case of fast neutrons. The same types of damage are produced by the two radiations: acidic and basic destruction of chromatin protein structure, DNA strand breaking and the increase of the distance between DNA and proteins in chromatin. (author)

  11. Radiation monitoring system for astronauts

    International Nuclear Information System (INIS)

    Thomson, I.; MacKay, G.; Ng, A.; Tomi, L.

    1996-01-01

    Astronauts in space are constantly under the bombardment of radiation particles from trapped electrons, and trapped proton. In addition, cosmic rays, while penetrating the spacecraft shell, generate secondary radiation of neutrons. As astronauts' stay in space is getting longer, the need for a real-time radiation monitoring device has become critical. Thermoluminescent dosemeter (TLD), used onboard both the MIR and the Space Transportation System (STS), cannot provide real-time dose reading. This paper describes a real-time direct read-out device, currently under development, which can measure skin, eye, and Blood Forming Organ (BFO) doses separately. (author)

  12. Radiation damage in CTR magnet components

    International Nuclear Information System (INIS)

    Ullmaier, H.

    1976-01-01

    Data are reviewed (already existing or to be acquired) which should allow prediction of the behavior of large superconducting coils in the radiation field of a future fusion reactor. The electrical and mechanical stability of such magnets is determined by the irradiation induced deterioration of the magnet components, i.e., (a) changes in critical current, field and temperature of the superconductor (NbTi, A-15 phases), (b) resistivity increase in the stabilizer (Cu, Al), and (c) changes in mechanical and dielectric properties of insulators and spacers. Recent low temperature simulation experiments (with fission neutrons and heavy ions) show that the superconductor will not be the critical component of a fusion magnet--at least as far as radiation damage is concerned. Much more severe is the loss of stability due to the resistivity increase of the stabilizing material. It seems, however, that the magnitude of this effect can be predicted rather reliably and therefore taken into account in the coil design. Almost no data exist about the low temperature behavior of insulator and spacer materials in a radiation field. Furthermore, very little is known about the nature of the radiation damage in non-metals, which makes extrapolations of the few existing data to other materials or to other doses highly speculative. Only future experiments can decide if the insulators will be the limiting component of a CTR magnet or not

  13. Biological monitoring of radiation exposure

    Science.gov (United States)

    Horneck, G.

    1998-11-01

    Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station.

  14. Ion - biomolecule interactions and radiation damage

    International Nuclear Information System (INIS)

    Schlathoelter, T.

    2004-01-01

    Full text: The biological effects of ionizing radiation in living cells are not a mere result of the direct impact of high energy quanta of radiation. Secondary particles such as low energy electrons, radicals and (multiply charged) ions are formed within the track. The interaction of these secondary particles with biologically relevant molecules is responsible for a large fraction of biological radiation damage to a cell, as well. Singly and multiply charged ions can be of importance as both, primary and secondary particles, and are known to cause severe biological damage. For instance, in heavy ion therapy and proton therapy the pronounced Bragg peak of fast (typically a few 100 MeV/u) ions in biological tissue is utilized. The Bragg peak is located at a depth, where the ions (mostly C q+ or protons) are slowed down to about 100 keV/u and have their maximum linear energy transfer (LET) to the medium. This depth is reasonably well defined and depends on the initial ion kinetic energy. Since the ions are rapidly stopped in this energy range, penetration beyond the Bragg peak is weak and it is thus possible to 'scan' the Bragg peak through a malignant tumour without excessive damage of the surrounding tissue by mere variation of the ion kinetic energy (i.e. the penetration depth). Severe biological damage is almost only possible, when the track of a primary quantum of ionizing radiation crosses the nucleus of a cell. Particularly the induction of double strand breaks of DNA or clustered DNA lesions is potentially lethal or mutagenic. A primary particle interacting with individual molecules within this environment leads to molecular excitation, ionization and fragmentation. In the process, the primary particle looses energy and slow secondary electrons and ions are formed, which might induce further damage. For a deep understanding of biological radiation damage on the level of individual molecules it is thus important to quantify excitation, ionization and

  15. Citizen-based environmental radiation monitoring network

    International Nuclear Information System (INIS)

    Alemayehu, B.; Mckinzie, M.; Cochran, T.; Sythe, D.; Randrup, R.; Lafargue, E.

    2017-01-01

    This paper discusses a Citizen Radiation Monitoring project designed and implemented by the Natural Resources Defense Council . The goal of the project was to implement a radiation monitoring system that provides radiation data accessible to the public. The monitoring system consisted of usage of a radiation detector integrated with near real-time data collection and visualization. The monitoring systems were installed at five different locations and background radiation measurements were taken. The developed monitoring system demonstrated that citizen-based monitoring system could provide accessible radiation data to the general public and relevant to the area where they live. (author)

  16. Monitoring occupational exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Button, J.B.C. [Radiation Safety Consultancy, Engadine, NSW (Australia)

    1997-12-31

    A brief overview is presented of methods of monitoring occupational exposure to ionizing radiation together with reasons for such monitoring and maintaining dose histories of radiation occupationally exposed persons. The various Australian providers of external radiation monitoring services and the types of dosemeters they supply are briefly described together with some monitoring results. Biological monitoring methods, are used to determine internal radiation dose. Whole body monitors, used for this purpose are available at Australian Radiation Lab., ANSTO and a few hospitals. Brief mention is made of the Australian National Radiation Dose Register and its objectives. 8 refs., 9 tabs.

  17. Monitoring occupational exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Button, J.B.C.

    1997-01-01

    A brief overview is presented of methods of monitoring occupational exposure to ionizing radiation together with reasons for such monitoring and maintaining dose histories of radiation occupationally exposed persons. The various Australian providers of external radiation monitoring services and the types of dosemeters they supply are briefly described together with some monitoring results. Biological monitoring methods, are used to determine internal radiation dose. Whole body monitors, used for this purpose are available at Australian Radiation Lab., ANSTO and a few hospitals. Brief mention is made of the Australian National Radiation Dose Register and its objectives

  18. Radiation area monitor device and method

    Science.gov (United States)

    Vencelj, Matjaz; Stowe, Ashley C.; Petrovic, Toni; Morrell, Jonathan S.; Kosicek, Andrej

    2018-01-30

    A radiation area monitor device/method, utilizing: a radiation sensor; a rotating radiation shield disposed about the radiation sensor, wherein the rotating radiation shield defines one or more ports that are transparent to radiation; and a processor operable for analyzing and storing a radiation fingerprint acquired by the radiation sensor as the rotating radiation shield is rotated about the radiation sensor. Optionally, the radiation sensor includes a gamma and/or neutron radiation sensor. The device/method selectively operates in: a first supervised mode during which a baseline radiation fingerprint is acquired by the radiation sensor as the rotating radiation shield is rotated about the radiation sensor; and a second unsupervised mode during which a subsequent radiation fingerprint is acquired by the radiation sensor as the rotating radiation shield is rotated about the radiation sensor, wherein the subsequent radiation fingerprint is compared to the baseline radiation fingerprint and, if a predetermined difference threshold is exceeded, an alert is issued.

  19. Radiation damage in silicon exposed to high-energy protons

    International Nuclear Information System (INIS)

    Davies, Gordon; Hayama, Shusaku; Murin, Leonid; Krause-Rehberg, Reinhard; Bondarenko, Vladimir; Sengupta, Asmita; Davia, Cinzia; Karpenko, Anna

    2006-01-01

    Photoluminescence, infrared absorption, positron annihilation, and deep-level transient spectroscopy (DLTS) have been used to investigate the radiation damage produced by 24 GeV/c protons in crystalline silicon. The irradiation doses and the concentrations of carbon and oxygen in the samples have been chosen to monitor the mobility of the damage products. Single vacancies (and self-interstitials) are introduced at the rate of ∼1 cm -1 , and divacancies at 0.5 cm -1 . Stable di-interstitials are formed when two self-interstitials are displaced in one damage event, and they are mobile at room temperature. In the initial stages of annealing the evolution of the point defects can be understood mainly in terms of trapping at the impurities. However, the positron signal shows that about two orders of magnitude more vacancies are produced by the protons than are detected in the point defects. Damage clusters exist, and are largely removed by annealing at 700 to 800 K, when there is an associated loss of broad band emission between 850 and 1000 meV. The well-known W center is generated by restructuring within clusters, with a range of activation energies of about 1.3 to 1.6 eV, reflecting the disordered nature of the clusters. Comparison of the formation of the X centers in oxygenated and oxygen-lean samples suggests that the J defect may be interstitial related rather than vacancy related. To a large extent, the damage and annealing behavior may be factorized into point defects (monitored by sharp-line optical spectra and DLTS) and cluster defects (monitored by positron annihilation and broadband luminescence). Taking this view to the limit, the generation rates for the point defects are as predicted by simply taking the damage generated by the Coulomb interaction of the protons and Si nuclei

  20. Studies on the strategies of minimizing radiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hee Yong; Sohn, Young Sook

    1998-04-01

    We studied on the strategies of minimizing radiation damage in animal system. To this end we studied following areas of research (1) mechanisms involved in bone marrow damage after total body irradiation, (2) extraction of components that are useful in protecting hematopoietic system from radiation damage, (3) cell therapy approach in restoring the damaged tissue, (4) development of radioprotective chemical reagent, and (5) epidemiological study on the population that had been exposed to radiation.

  1. Studies on the strategies of minimizing radiation damage

    International Nuclear Information System (INIS)

    Chung, Hee Yong; Sohn, Young Sook

    1998-04-01

    We studied on the strategies of minimizing radiation damage in animal system. To this end we studied following areas of research 1) mechanisms involved in bone marrow damage after total body irradiation, 2) extraction of components that are useful in protecting hematopoietic system from radiation damage, 3) cell therapy approach in restoring the damaged tissue, 4) development of radioprotective chemical reagent, and 5) epidemiological study on the population that had been exposed to radiation

  2. Compilation of radiation damage test data. I

    International Nuclear Information System (INIS)

    Schoenbacher, H.; Stolarz-Izycka, A.

    1979-01-01

    This report summarizes radiation damage test data on commercially available organic cable insulation and jacket materials: ethylene-propylene rubber, Hypalon, neoprene rubber, polyethylene, polyurethane, polyvinylchloride, silicone rubber, etc. The materials have been irradiated in a nuclear reactor to integrated absorbed doses from 5 X 10 5 to 5 X 10 6 Gy. Mechanical properties, e.g. tensile strength, elongation at break, and hardness, have been tested on irradiated and non-irradiated samples. The results are presented in the form of tables and graphs, to show the effect of the absorbed dose on the measured properties. (Auth.)

  3. Radiation damage to DNA-protein complexes

    Czech Academy of Sciences Publication Activity Database

    Spotheim-Maurizot, M.; Davídková, Marie

    2011-01-01

    Roč. 261, zima (2011), s. 1-10 ISSN 1742-6588. [COST Chemistry CM0603-MELUSYN Joint Meeting Damages Induced in Biomolecules by Low and High Energy Radiations. Paříž, 09.03.2010-12.03.2010] R&D Projects: GA AV ČR IAA1048103; GA AV ČR KJB4048401; GA MŠk 1P05OC085; GA MŠk OC09012; GA AV ČR IAB1048901 Institutional research plan: CEZ:AV0Z10480505 Keywords : radiolysis * molecular-dynamics simulation * hydroxyl radical attack * induced strand breakage Subject RIV: BO - Biophysics

  4. Ultraviolet radiation, sun damage and preventing

    International Nuclear Information System (INIS)

    Johnsen, B.; Christensen, T.; Nilsen, L.T.; Hannevik, M.

    2013-01-01

    The report focuses on the large impact of health damages due to excessive UV exposure from natural sun. The first part of the report gives background information on factors significantly affecting the intensity of UV radiation. The second part gives an overview of health effects related to UV exposure, with recommendations on how to avoid excessive UV exposure and still enjoy the positive sides of outdoor activity. The report is intended to contribute to informational activities about sun exposure as recommended by the World Health Organisation and the World Meteorology Organisation. (Author)

  5. Radiation damage calculations for the LANSCE degrader

    International Nuclear Information System (INIS)

    Ferguson, P.D.; Sommer, W.F.; Dudziak, D.J.; Wechsler, M.S.; Barnett, M.H.; Corzine, R.K.

    1998-01-01

    The A-6 water degrader at the Los Alamos Neutron Science Center (LANSCE) linear proton accelerator has an outer shell of Inconel 718. The degrader was irradiated by 800-MeV protons during 1988--1993 to an exposure of 5.3 ampere-hours (A h). As described in Ref. 1, material from the Inconel is currently being cut into specimens for microhardness, three-point bending, ball punch, microscopy, and corrosion tests. This paper is devoted to calculations of radiation damage, particularly displacement and He production, sustained by the degrader Inconel

  6. Neutron radiation damage studies on silicon detectors

    International Nuclear Information System (INIS)

    Li, Zheng; Chen, W.; Kraner, H.W.

    1990-10-01

    Effects of neutron radiation on electrical properties of Si detectors have been studied. At high neutron fluence (Φ n ≥ 10 12 n/cm 2 ), C-V characteristics of detectors with high resistivities (ρ ≥ 1 kΩ-cm) become frequency dependent. A two-trap level model describing this frequency dependent effect is proposed. Room temperature anneal of neutron damaged (at LN 2 temperature) detectors shows three anneal stages, while only two anneal stages were observed in elevated temperature anneal. 19 refs., 14 figs

  7. Ultraviolet Radiations: Skin Defense-Damage Mechanism.

    Science.gov (United States)

    Mohania, Dheeraj; Chandel, Shikha; Kumar, Parveen; Verma, Vivek; Digvijay, Kumar; Tripathi, Deepika; Choudhury, Khushboo; Mitten, Sandeep Kumar; Shah, Dilip

    2017-01-01

    UV-radiations are the invisible part of light spectra having a wavelength between visible rays and X-rays. Based on wavelength, UV rays are subdivided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (200-280 nm). Ultraviolet rays can have both harmful and beneficial effects. UV-C has the property of ionization thus acting as a strong mutagen, which can cause immune-mediated disease and cancer in adverse cases. Numbers of genetic factors have been identified in human involved in inducing skin cancer from UV-radiations. Certain heredity diseases have been found susceptible to UV-induced skin cancer. UV radiations activate the cutaneous immune system, which led to an inflammatory response by different mechanisms. The first line of defense mechanism against UV radiation is melanin (an epidermal pigment), and UV absorbing pigment of skin, which dissipate UV radiation as heat. Cell surface death receptor (e.g. Fas) of keratinocytes responds to UV-induced injury and elicits apoptosis to avoid malignant transformation. In addition to the formation of photo-dimers in the genome, UV also can induce mutation by generating ROS and nucleotides are highly susceptible to these free radical injuries. Melanocortin 1 receptor (MC1R) has been known to be implicated in different UV-induced damages such as pigmentation, adaptive tanning, and skin cancer. UV-B induces the formation of pre-vitamin D3 in the epidermal layer of skin. UV-induced tans act as a photoprotection by providing a sun protection factor (SPF) of 3-4 and epidermal hyperplasia. There is a need to prevent the harmful effects and harness the useful effects of UV radiations.

  8. Radiation monitoring network in Poland

    International Nuclear Information System (INIS)

    Grabowski, D.; Kurowski, W.; Muszynski, W.; Rubel, B.; Smagala, G.; Swietochowska, J.

    2001-01-01

    In Poland the radioactive contamination of the environment and food has been controlled since the early sixties by the Service for Measurements of Radioactive Contamination (SPSP). The service comprises a network of measuring stations and the Centre of Radioactive Contamination Measurements (COPSP). Actually, there are 100 measurement stations. The main task of such station is systematic measurement of radioactivity level in samples of environment components and food. Nine stations of SPSP acting within meteorological stations, ten stations of low level air radioactivity measurements (Aerosols Sampling Stations-500) and eleven permanent monitoring stations (PMS) form the radiation monitoring warning system in Poland. (author)

  9. Radiation damage in non-metals

    International Nuclear Information System (INIS)

    Stoneham, A.M.

    1980-01-01

    Work on the problem of radiation damage in non-metals over the past 25 years is reviewed with especial emphasis on the contribution made at AERE, Harwell and in particular by members of the Theoretical Physics Division. In the years between 1954 and the end of the 1960's the main thrust in the radiation damage of non-metals was model-building including devising defect models and mechanisms that were qualitatively acceptable, and compiling systematic data. The early 1970's made greater quantitative demands as computer techniques made theory more powerful. In many cases it was possible to predict defect properties accurately, so that one could distinguish between different defect models which were hard to tell apart by experiment alone. In the late 1970's the most important aspect has moved towards mechanisms of defect processes, especially in cases where experiment by itself is limited by timescale, by complexity, by the unintentional impurities inevitable in real crystals, or by the extreme conditions required. (UK)

  10. Evaluation of the radiation monitor

    International Nuclear Information System (INIS)

    1996-05-01

    The Radiation Monitor is an information bulletin produced every three months by the Atomic Energy Control Board (AECB) and published in five local newspapers in the Durham Region of Ontario. The bulletin reports on the radiation doses to the public due to emissions from Pickering and Darlington nuclear generating stations. Comparative information on dose levels from other sources is also provided. To measure the communications effectiveness of the bulletin, the AECB contracted for a door-to-door survey of residents living near the two nuclear stations and within the circulation areas of the five local papers. The objectives of the survey were to measure the public's awareness of the existence of the Radiation Monitor, evaluate ease in understanding the information, assess the perceived usefulness of the bulletin, and assess the perceived accessibility of the AECB as an information source. The survey found that 61 per cent of adults had heard of the AECB, and 60 per cent of those correctly identified it as a regulator of the nuclear industry. Six per cent of the surveyed population had accurate unaided recall of the Radiation Monitor, while 26 per cent recognized the bulletin when shown a copy. Most respondents to the survey seemed content with the way technical details are presented in the bulletin, and 85 per cent of all persons interviewed found the information it contained to be useful. Thirty-six per cent said that it was very useful. For many, the bulletin was seen to put radiation in perspective and to reassure residents of the low risk. It was also judged by most to be factual and easy to understand. Suggestions for improvement focus largely on improving distribution. 14 tabs

  11. Evaluation of the radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The Radiation Monitor is an information bulletin produced every three months by the Atomic Energy Control Board (AECB) and published in five local newspapers in the Durham Region of Ontario. The bulletin reports on the radiation doses to the public due to emissions from Pickering and Darlington nuclear generating stations. Comparative information on dose levels from other sources is also provided. To measure the communications effectiveness of the bulletin, the AECB contracted for a door-to-door survey of residents living near the two nuclear stations and within the circulation areas of the five local papers. The objectives of the survey were to measure the public`s awareness of the existence of the Radiation Monitor, evaluate ease in understanding the information, assess the perceived usefulness of the bulletin, and assess the perceived accessibility of the AECB as an information source. The survey found that 61 per cent of adults had heard of the AECB, and 60 per cent of those correctly identified it as a regulator of the nuclear industry. Six per cent of the surveyed population had accurate unaided recall of the Radiation Monitor, while 26 per cent recognized the bulletin when shown a copy. Most respondents to the survey seemed content with the way technical details are presented in the bulletin, and 85 per cent of all persons interviewed found the information it contained to be useful. Thirty-six per cent said that it was very useful. For many, the bulletin was seen to put radiation in perspective and to reassure residents of the low risk. It was also judged by most to be factual and easy to understand. Suggestions for improvement focus largely on improving distribution. 14 tabs.

  12. Radiation damage to DNA-binding proteins

    International Nuclear Information System (INIS)

    Culard, G.; Eon, S.; DeVuyst, G.; Charlier, M.; Spotheim-Maurizot, M.

    2003-01-01

    The DNA-binding properties of proteins are strongly affected upon irradiation. The tetrameric lactose repressor (a dimer of dimers) losses its ability to bind operator DNA as soon as at least two damages per protomer of each dimer occur. The monomeric MC1 protein losses its ability to bind DNA in two steps : i) at low doses only the specific binding is abolished, whereas the non-specific one is still possible; ii) at high doses all binding vanishes. Moreover, the DNA bending induced by MC1 binding is less pronounced for a protein that underwent the low dose irradiation. When the entire DNA-protein complexes are irradiated, the observed disruption of the complexes is mainly due to the damage of the proteins and not to that of DNA. The doses necessary for complex disruption are higher than those inactivating the free protein. This difference, larger for MC1 than for lactose repressor, is due to the protection of the protein by the bound DNA. The oxidation of the protein side chains that are accessible to the radiation-induced hydroxyl radicals seems to represent the inactivating damage

  13. Investigation of solar cell radiation damage

    International Nuclear Information System (INIS)

    Bernard, J.; Reulet, R.; Arndt, R.A.

    1974-01-01

    Development of communications satellites has led to the requirement for a greater and longer lived solar cell power source. Accordingly, studies have been undertaken with the aim of determining which solar cell array provides the greatest power at end of life and the amount of degradation. Investigation of the damage done to thin silicon and thin film CdS solar cells is being carried out in two steps. First, irradiations were performed singly with 0.15, 1.0 and 2.0MeV electrons and 0.7, 2.5 and 22MeV proton. Solar cells and their cover materials were irradiated separately in order to locate the sites of the damage. Diffusion length and I.V. characteristics of the cells and transmission properties of the cover materials were measured. All neasurements were made in vacuum immediately after irradiation. In the second part it is intended to study the effect of various combinations of proton, electron and photon irradiation both with and without an electrical load. The results of this part show whether synergism is involved in solar cell damage and the relative importance of each of three radiation sources if synergism is found [fr

  14. Solar radiation and mitochondrial DNA damage

    International Nuclear Information System (INIS)

    Hill, H.Z.; Locitzer, J.; Nassrin, E.; Ogbonnaya, A.; Hubbard, K.

    2003-01-01

    The 16.6 kB human mitochondrial DNA contains two homologous 13 base pair direct repeats separated by about 5 kB. During asynchronous mitochondrial DNA replication, the distant repeat sequences are thought to anneal, resulting in the looping out of a portion of the non-template strand which is subsequently deleted as a result of interaction with reactive oxygen species (ROS). A normal daughter and a deleted daughter mitochondrion result from such insults. This deletion has been termed the common deletion as it is the most frequent of the known mitochondrial DNA deletions. The common deletion is present in high frequency in several mitochondrial disorders, accumulates with age in slow turnover tissues and is increased in sun-exposed skin. Berneburg, et al. (Photochem. Photobiol. 66: 271, 1997) induced the common deletion in normal human fibroblasts after repeated exposures to UVA. In this study, the common deletion has been shown to be induced by repeated non-lethal exposures to FS20 sunlamp irradiation. Increases in the common deletion were demonstrated using nested PCR which produced a 303 bp product that was compared to a 324 bp product that required the presence of the undeleted 5 kB region. The cells were exposed to 10 repeated doses ranging from 0.5 (UVB) - 0.24 (UVA) J/sq m to 14.4 (UVB) - 5.8 J/sq m (UVA) measured using a UVX digital radiometer and UVB and UVA detectors respectively. Comparison with the earlier study by Berneberg, et al. suggests that this type of simulated solar damage is considerably more effective in fewer exposures than UVA radiation alone. The common deletion provides a cytoplasmic end-point for ROS damage produced by low dose chronic irradiations and other low level toxic exposures and should prove useful in evaluating cytoplasmic damage produced by ionizing radiation as well

  15. Molecular mechanisms in radiation damage to DNA: Final report

    International Nuclear Information System (INIS)

    Osman, R.

    1996-01-01

    The objectives of this work were to elucidate the molecular mechanisms that were responsible for radiation-induced DNA damage. The studies were based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA

  16. Radiation monitor training program at Rocky Flats

    International Nuclear Information System (INIS)

    Medina, L.C.; Kittinger, W.D.; Vogel, R.M.

    The Rocky Flats Radiation Monitor Training Program is tailored to train new health physics personnel in the field of radiation monitoring. The purpose of the prescribed materials and media is to be consistent in training in all areas of Rocky Flats radiation monitoring job involvement

  17. The design of radiation monitor passageway system

    International Nuclear Information System (INIS)

    Chu Chengsheng

    2006-10-01

    The Radiation Monitor Passageway System is designed as four modules, the radiation detection modules, the control modules, the mechanism modules and the optional modules. this system integrate the radiation detection technology and door ban control technology. It is a effective radiation monitor equipment with high detect sensitiveness, it will be hopeful devoted to national nuclear safeguard. (authors)

  18. Thermal Decomposition of Radiation-Damaged Polystyrene

    International Nuclear Information System (INIS)

    J Abrefah, J.; Klinger, G.S.

    2000-01-01

    The radiation-damaged polystyrene material (''polycube'') used in this study was synthesized by mixing a high-density polystyrene (''Dylene Fines No. 100'') with plutonium and uranium oxides. The polycubes were used on the Hanford Site in the 1960s for criticality studies to determine the hydrogen-to-fissile atom ratios for neutron moderation during processing of spent nuclear fuel. Upon completion of the studies, two methods were developed to reclaim the transuranic (TRU) oxides from the polymer matrix: (1) burning the polycubes in air at 873 K; and (2) heating the polycubes in the absence of oxygen and scrubbing the released monomer and other volatile organics using carbon tetrachloride. Neither of these methods was satisfactory in separating the TRU oxides from the polystyrene. Consequently, the remaining polycubes were sent to the Hanford Plutonium Finishing Plant (PFP) for storage. Over time, the high dose of alpha and gamma radiation has resulted in a polystyrene matrix that is highly cross-linked and hydrogen deficient and a stabilization process is being developed in support of Defense Nuclear Facility Safety Board Recommendation 94-1. Baseline processes involve thermal treatment to pyrolyze the polycubes in a furnace to decompose the polystyrene and separate out the TRU oxides. Thermal decomposition products from this degraded polystyrene matrix were characterized by Pacific Northwest National Laboratory to provide information for determining the environmental impact of the process and for optimizing the process parameters. A gas chromatography/mass spectrometry (GC/MS) system coupled to a horizontal tube furnace was used for the characterization studies. The decomposition studies were performed both in air and helium atmospheres at 773 K, the planned processing temperature. The volatile and semi-volatile organic products identified for the radiation-damaged polystyrene were different from those observed for virgin polystyrene. The differences were in the

  19. Radiation monitoring of PET staff

    International Nuclear Information System (INIS)

    Trang, A.

    2004-01-01

    Full text: Positron emission tomography (PET) is becoming a common diagnostic tool in hospitals, often located in and employing staff from the Nuclear Medicine or Radiology departments. Although similar in some ways, staff in PET departments are commonly found to have the highest radiation doses in the hospital environment due to unique challenges which PET tracers present in administration as well as production. The establishment of a PET centre with a dedicated cyclotron has raised concerns of radiation protection to the staff at the WA PET Centre and the Radiopharmaceutical Production and Development (RAPID) team. Since every PET centre has differing designs and practices, it was considered important to closely monitor the radiation dose to our staff so that improvements to practices and design could be made to reduce radiation dose. Electronic dosimeters (MGP DMC 2000XB), which have a facility to log time and dose at 10 second intervals, were provided to three PET technologists and three PET nurses. These were worn in the top pocket of their lab coats throughout a whole day. Each staff member was then asked to note down their duties throughout the day and also note the time they performed each duty. The duties would then correlate with the dose with which the electronic monitor recorded and an estimate of radiation dose per duty could be given. Also an estimate of the dose per day to each staff member could be made. PET nurses averaged approximately 20 μ8v per day getting their largest dose from caring for occasional problematic patients. Smaller doses of a 1-2 μ8v were recorded for injections and removing cannulas. PET technologists averaged approximately 15 μ8v per day getting their largest dose of 1-5μ8v mainly from positioning of patients and sometimes larger doses due to problematic patients. Smaller doses of 1-2 μ5v were again recorded for injections and removal of cannulas. Following a presentation given to staff, all WA PET Centre and RAPID staff

  20. Radiation monitoring of uranium workers

    International Nuclear Information System (INIS)

    1998-12-01

    In order to manage radiological hazards in the workplace, it is necessary to have reliable measurements of workplace radiation levels and estimates of exposures and doses to workers. Over the past several years there have been many changes not only to the science of monitoring and dose assessment, but also to the regulatory framework. New International Commission on Radiological Protection (ICRP) recommendations on dose in ICRP Publication 60 (1991) and the implications of the ICRP's new respiratory tract model in ICRP Publication 66 (1994) are of particular importance. In addition, triggered by the act establishing the Canadian Nuclear Safety Commission (CNSC), which will replace the Atomic Energy Control Board (AECB), there is considerable activity in the review and development of regulatory guidance. Concurrent with these activities is the introduction of innovative mining procedures in Saskatchewan in order to extract uranium ore of particularly high grade. In view of these developments, the ACRP considered that a formal review of current monitoring practices would benefit both the CNSC and its licensees. In this report, 'uranium workers' refers to workers at uranium mines and mills, and workers at natural-uranium refineries, conversion, and fuel fabrication facilities; issues relating to long-term tailings management and to the handling of enriched materials are not addressed in this document. The report will have some relevance to workers in non-uranium mines and in industries handling naturally occurring radioactive materials (NORM) since, in some circumstances, these activities can present similar workplace radiation hazards. The report outlines the radiological hazards encountered in the Canadian uranium industry, and reviews current radiological monitoring practices and options; appendices include a glossary, a more technical discussion of monitoring methods, and an examination of errors and uncertainties in measurements of radon progeny and long

  1. Computer simulations of radiation damage in protein crystals

    International Nuclear Information System (INIS)

    Zehnder, M.

    2007-03-01

    The achievable resolution and the quality of the dataset of an intensity data collection for structure analysis of protein crystals with X-rays is limited among other factors by radiation damage. The aim of this work is to obtain a better quantitative understanding of the radiation damage process in proteins. Since radiation damage is unavoidable it was intended to look for the optimum ratio between elastically scattered intensity and radiation damage. Using a Monte Carlo algorithm physical processes after an inelastic photon interaction are studied. The main radiation damage consists of ionizations of the atoms through the electron cascade following any inelastic photon interaction. Results of the method introduced in this investigation and results of an earlier theoretical studies of the influence of Auger-electron transport in diamond are in a good agreement. The dependence of the radiation damage as a function of the energy of the incident photon was studied by computer-aided simulations. The optimum energy range for diffraction experiments on the protein myoglobin is 10-40 keV. Studies of radiation damage as a function of crystal volume and shape revealed that very small plate or rod shaped crystals suffer less damage than crystals formed like a cube with the same volume. Furthermore the influence of a few heavy atoms in the protein molecule on radiation damage was examined. Already two iron atoms in the unit cell of myoglobin increase radiation damage significantly. (orig.)

  2. Radiation Damage In Reactor Cavity Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G [ORNL; Le Pape, Yann [ORNL; Naus, Dan J [ORNL; Remec, Igor [ORNL; Busby, Jeremy T [ORNL; Rosseel, Thomas M [ORNL; Wall, Dr. James Joseph [Electric Power Research Institute (EPRI)

    2015-01-01

    License renewal up to 60 years and the possibility of subsequent license renewal to 80 years has established a renewed focus on long-term aging of nuclear generating stations materials, and recently, on concrete. Large irreplaceable sections of most nuclear generating stations include concrete. The Expanded Materials Degradation Analysis (EMDA), jointly performed by the Department of Energy, the Nuclear Regulatory Commission and Industry, identified the urgent need to develop a consistent knowledge base on irradiation effects in concrete. Much of the historical mechanical performance data of irradiated concrete does not accurately reflect typical radiation conditions in NPPs or conditions out to 60 or 80 years of radiation exposure. To address these potential gaps in the knowledge base, The Electric Power Research Institute and Oak Ridge National Laboratory are working to disposition radiation damage as a degradation mechanism. This paper outlines the research program within this pathway including: (i) defining the upper bound of the neutron and gamma dose levels expected in the biological shield concrete for extended operation (80 years of operation and beyond), (ii) determining the effects of neutron and gamma irradiation as well as extended time at temperature on concrete, (iii) evaluating opportunities to irradiate prototypical concrete under accelerated neutron and gamma dose levels to establish a conservative bound and share data obtained from different flux, temperature, and fluence levels, (iv) evaluating opportunities to harvest and test irradiated concrete from international NPPs, (v) developing cooperative test programs to improve confidence in the results from the various concretes and research reactors, (vi) furthering the understanding of the effects of radiation on concrete (see companion paper) and (vii) establishing an international collaborative research and information exchange effort to leverage capabilities and knowledge.

  3. Uzbekistan Radiation Portal Monitoring System

    International Nuclear Information System (INIS)

    Richardson, J; Knapp, R; Loshak, A; Yuldashev, B; Petrenko, V

    2005-01-01

    The work proposed in this presentation builds on the foundation set by the DTRA funded demonstration project begun in 2000 and completed in December of 2003. This previous work consisted of two phases whose overall objective was to install portal radiation monitors at four select ports-of-entry in Uzbekistan (Tashkent International Airport, Gisht-Kuprik (Kazakhstan border), Alat (Turkmenistan border), and Termez (Afghanistan border)) in order to demonstrate their effectiveness in preventing the illicit trafficking of nuclear materials. The objectives also included developing and demonstrating capabilities in the design, installation, operation, training, and maintenance of a radiation portal monitoring system. The system and demonstration project has proved successful in many ways. An effective working relationship among the Uzbekistan Customs Services, Uzbekistan Border Guards, and Uzbekistan Institute of Nuclear Physics has been developed. There has been unprecedented openness with the sharing of portal monitor data with Lawrence Livermore National Laboratory. The system has proved to be effective, with detection of illicit trafficking, and, at Alat, an arrest of three persons illegally transporting radioactive materials into Turkmenistan. The demonstration project has made Uzbekistan a model nonproliferation state in Central Asia and, with an expanded program, places them in a position to seal a likely transit route for illicit nuclear materials. These results will be described. In addition, this work is currently being expanded to include additional ports-of-entry in Uzbekistan. The process for deciding on which additional ports-of-entry to equip will also be described

  4. Compilation of radiation damage test data

    International Nuclear Information System (INIS)

    Schoenbacher, H.; Tavlet, M.

    1989-01-01

    This report summarizes radiation damage test data on commercially available organic cable insulation and jacket materials: Ethylene-propylene rubbers, polyethylenes, polyurethanes, silicone rubbers, and copolymers based on polyethylene. The materials have been irradiated either in a nuclear reactor, or with a cobalt-60 source, or in the CERN accelerators, at different dose rates. The absorbed doses were between 10 3 and 5x10 6 Gy. Mechanical properties, e.g. tensile strength, elongation at break, and hardness, have been tested on irradiated and non-irradiated samples, according to the recommendations of the International Electrotechnical Commission. The results are presented in the form of tables and graphs to show the effect of the absorbed dose on the measured properties. (orig.)

  5. Compilation of radiation damage test data. II

    International Nuclear Information System (INIS)

    Schoenbacher, H.; Stolarz-Izycka, A.

    1979-01-01

    This report summarizes radiation damage test data on thermosetting and thermoplastic resins, with the main emphasis on epoxy resins used for magnet coil insulations. Also, other materials such as polyesters, phenolics, polyurethanes, silicones, etc., are represented. The materials have been irradiated in a nuclear reactor to integrated absorbed doses between 5x10 6 Gy and 1x10 8 Gy. The mechanical properties, e.g. the flexural strength, deflection at break, and tangent modulus of elasticity, have been measured on irradiated and non-irradiated samples. The results are given as variation of these parameters versus absorbed dose and are presented in the form of tables and graphs. The tested materials are catalogued in alphabetical order. (Auth.)

  6. Protection of DNA damage by radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Ho; Kim, In Gyu; Lee, Kang Suk; Kim, Kug Chan; Oh, Tae Jung

    1998-12-01

    The SOS response of Escherichia coli is positively regulated by RecA. To examine the effects of polyamines on The SOS response of E. Coli, we investigated the expression of recA gene in polyamine-deficient mutant and wild type carrying recA'::lacZ fusion gene. As a result, recA expression by mitomycin C is higher in wild type than that of polyamine-deficient mutant, but recA expression by UV radiation is higher in wild type than of mutant. We also found that exogenous polyamines restored the recA expression in the polyamine-deficient mutant to the wild type level. These results proposed that polyamines play an important role in mechanism of intracellular DNA protection by DNA damaging agents.

  7. Protection of DNA damage by radiation exposure

    International Nuclear Information System (INIS)

    Lee, Jeong Ho; Kim, In Gyu; Lee, Kang Suk; Kim, Kug Chan; Oh, Tae Jung

    1998-12-01

    The SOS response of Escherichia coli is positively regulated by RecA. To examine the effects of polyamines on The SOS response of E. Coli, we investigated the expression of recA gene in polyamine-deficient mutant and wild type carrying recA'::lacZ fusion gene. As a result, recA expression by mitomycin C is higher in wild type than that of polyamine-deficient mutant, but recA expression by UV radiation is higher in wild type than of mutant. We also found that exogenous polyamines restored the recA expression in the polyamine-deficient mutant to the wild type level. These results proposed that polyamines play an important role in mechanism of intracellular DNA protection by DNA damaging agents

  8. Protection of DNA damage by radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Ho; Kim, In Gyu; Lee, Kang Suk; Kim, Kug Chan; Oh, Tae Jung

    1998-12-01

    The SOS response of Escherichia coli is positively regulated by RecA. To examine the effects of polyamines on The SOS response of E. Coli, we investigated the expression of recA gene in polyamine-deficient mutant and wild type carrying recA'::lacZ fusion gene. As a result, recA expression by mitomycin C is higher in wild type than that of polyamine-deficient mutant, but recA expression by UV radiation is higher in wild type than of mutant. We also found that exogenous polyamines restored the recA expression in the polyamine-deficient mutant to the wild type level. These results proposed that polyamines play an important role in mechanism of intracellular DNA protection by DNA damaging agents.

  9. Monitoring of radiation via CT

    International Nuclear Information System (INIS)

    Atzinger, A.; Pfaendner, K.; Gfirtner, H.; Hoetzinger, H.

    1981-01-01

    The results presented in this article lead to the conclusion that it would be appropriate to demand control or monitoring of radiation via CT whenever complicated exposure to radiation is required. Such control appears mandatory in order to guarantee a sufficiently high tumour dosage and satisfactory protection or minimum burdening of the surrounding tissue. At first sight, it may seem that such CT operations are relatively costly. However, once the teamwork has been properly established, both the time required and the cost involved remain within reasonable limits and will probably not be greater than control via therapy simulator. The decisive factor is that computerised tomography should offer sufficient possibilities of translating such control into reality by effecting the necessary dosage adjustments in accordance with given requirements. (orig.) [de

  10. Spallation radiation damage and the radiation damage facility at the LAMPF A-6 target station

    Energy Technology Data Exchange (ETDEWEB)

    Wechsler, M.S.; Sommer, W.F. (Los Alamos National Lab., NM (USA))

    1984-05-01

    A redesign of the Clinton P. Anderson Los Alamos Meson Physics Facility (LAMPF) A-6 Target Station is underway that will permit materials irradiations to be conducted in the proton beam and in the spallation neutron environment under more controlled conditions than has been possible heretofore. The protons of energy near 800 MeV and beam current approaching one mA are able to produce radiation damage rates (displacement production rates) as high as can be achieved in fission reactors, and the damage is uniform over macroscopic dimensions. The spallation neutrons have a degraded fission spectrum energy distribution, with the important admixture of a high energy tail up to 800 MeV. Irradiations in these radiation environments can be used to address important problems in the development of materials for fusion reactors. The redesign of the A-6 Target Station is described and plans for its use are discussed.

  11. Radiation monitoring at Pakistan research reactor

    International Nuclear Information System (INIS)

    Ali, A.

    1984-05-01

    Area radiation monitoring is accomplished by using Tracer Lab. radiation monitor. Personnel monitoring is carried out using film badges, TLDs (Thermoluminescent Dosimeters) and pocket dosimeters. For the evaluation of monthly accumulated doses of radiation workers film badges/TLDs and for instantaneous/short term dose measurement in higher radiation zones pocket dosimeters are used in addition to film badge/TLD. Environmental monitoring is necessary to check the PARR operation effect on background radiation level in the vicinity of PINSTECH. (A.B.). 4 refs

  12. The purpose of radiation protection monitoring

    International Nuclear Information System (INIS)

    Morgan, K.Z.

    1979-01-01

    In the early period (1942-1960) of nuclear energy programmes with which I was associated, most radiation protection standards seem to have been formulated on the assumption that there is a threshold dose of ionizing radiation below which no radiation damage is expected to result in the lifetime of the exposed individual. It was in this climate of opinion that health physics began as a profession, and levels of maximum permissible exposure (MPE) to external sources of radiation, maximum permissible concentrations in air, water and food, and maximum permissible body burdens of radionuclides inside the human body were set and enforced. Some of the levels of MPE were quite high in comparison with present standards but, fortunately, the health physicists at the national laboratories in which most radiation workers were employed were very conservative; in most cases the average annual exposures were less than 10% of the MPE levels. However, there was not much concern with the man-rem concept, as exemplified by rather high levels of radioactive waste discharged from the plants or placed in temporary holding facilities - where there was a likely possibility of seepage into the environment. This situation was understandable and justifiable at a time when the purpose of radiation protection monitoring was simply to prevent individuals from exceeding a threshold dose. The period of the recent past up to the present time (1978) has been one in which there has been a gradual change from the concept of a threshold dose hypothesis to the linear hypothesis. In this period the International Commission on Radiological Protection (ICRP) and the national standards setting bodies have pointed out that the levels they have selected are based on the linear hypothesis, but in most respects they leave us with the impression that this is most probably a conservative assumption, subject to revision when better data become available. Also, during this period, the concept of exposure As Low As

  13. Basic principles for occupational radiation monitoring

    International Nuclear Information System (INIS)

    1987-01-01

    This Safety Guide sets forth the objectives of an adequate strategy for monitoring internal and external radiation exposures of workers. It covers individual monitoring, and workplace monitoring to the extent required for assessment and control of individual radiation doses. The responsibilities of authorities for organizing the monitoring of radiation workers are discussed, and brief descriptions are given of the rules governing the implementation of monitoring methods. The general principles to be considered in selecting instrumentation and appropriate monitoring techniques are described, as well as calibrating techniques, methods of record keeping and related aspects

  14. Radiation monitoring: an introduction. Rev. ed.

    International Nuclear Information System (INIS)

    Hayward, P.; Arnott, D.

    1987-01-01

    This Greenpeace pamphlet has been produced in reponse to requests from members of the public wishing to set up monitoring groups. It lists some U.K. manufacturers of radiation monitoring equipment and the contributors have summarized information available from manufacturer's own catalogues describing the equipment, what it will and will not do and costing various programmes. Three types of monitoring are discussed: monitoring the level of background gamma radiation, monitoring radioactive contamination, (early warning systems), and monitoring food and environmental samples for very low levels of radiation. (UK)

  15. Radiation damage: special reference to gas filled radiation detectors

    International Nuclear Information System (INIS)

    Gaur, Sudha; Joshi, Pankaj Kumar; Rathore, Shakuntla

    2012-01-01

    Radiation damage is a term associated with ionizing radiation. In gas filled particle detectors, radiation damage to gases plays an important role in the device's ageing, especially in devices exposed to high intensity radiation, e.g. detector for the large hadrons collide. Ionization processes require energy above 10 eV, while splitting covalent bond in molecules and generating free radical require only 3-4 eV. The electrical discharges initiated by the ionization event by the particles result in plasma populated by large amount of free radical. The highly reactive free radical can recombine back to original molecules, or initiate a chain of free radical polymerization reaction with other molecules, yielding compounds with increasing molecular weight. These high molecular weight compounds then precipitate from gases phase, forming conductive or non-conductive deposits on the electrodes an insulating surfaces of the detector and distorting it's response. Gases containing hydrocarbon quenchers, e.g. argon-methane, are typically sensitive to ageing by polymerization; addition of oxygen tends to lower the ageing rates. Trace amount of silicon oils, present form out gassing of silicon elastomers and especially from traces of silicon lubricant tend to decompose and form deposits of silicon crystals on the surfaces. Gases mixture of argon (or xenon) with CO 2 and optimally also with 2-3 % of oxygen are highly tolerant to high radiation fluxes. The oxygen is added as noble gas with CO 2 has too high transparency for high energy photons; ozone formed from the oxygen is a strong absorber of ultra violet photons. Carbon tetra fluoride can be used as a component of the gas for high-rate detectors; the fluorine radical produced during the operation however limit the choice of materials for the chambers and electrodes (e.g. gold electrodes are required, as the fluorine radicals attack metals, forming fluorides). Addition of carbon tetra fluoride can however eliminate the

  16. Use of heavy ions to model radiation damage of metals

    International Nuclear Information System (INIS)

    Shirokov, S.V.; Vyshemirskij, M.P.

    2011-01-01

    The methods for modeling radiation damage of metals using heavy ions are reviewed and the results obtained are analyzed. It is shown that irradiation of metals with heavy ion can simulate neutron exposure with the equivalent dose with adequate accuracy and permits a detailed analysis of radiation damage of metals

  17. Constructive and critical approach of the radiation damage simulation

    International Nuclear Information System (INIS)

    Becquart, Ch.

    2002-11-01

    This work deals with the problem of radiation damage in materials for applications in development of fission and nuclear fusion technologies. It is organised in 3 sections. In section 1 are presented the mechanisms of formation and the evolution kinetics of the primary damage. Section 2 is devoted to the study of the sensitivity of the radiation damage at different approximations. Section 3 discusses the contribution of the ab initio calculations to the study of radiation damage and more particularly the point defects in a dilute Fe-Cu ferritic alloy. This work is illustrated by several publications added in each section. (O.M.)

  18. Update on the independent radiation monitor (IRM)

    International Nuclear Information System (INIS)

    Kroening, P.M.; Mucha, R.

    1976-01-01

    The new independent radiation monitor (IRM), unlike its predecessor, is a reliable and sensitive safety device for any radiation therapy room. It shows unequivocally that the beam is on, and it is inexpensive and simple to construct

  19. Integrated nuclear radiation detector and monitor

    International Nuclear Information System (INIS)

    Biehl, B.L.; Lieberman, S.I.

    1982-01-01

    A battery powered device which can continuously monitor and detect nuclear radiation utilizing fully integrated circuitry and which is provided with an alarm which alerts persons when the radiation level exceeds a predetermined threshold

  20. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1991-12-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the third quarter of 1991

  1. Study concerning an integrated radiation monitoring systems for nuclear facilities

    International Nuclear Information System (INIS)

    Oprea, I.; Oprea, M.; Stoica, M.; Cerga, V.; Pirvu, V; Badea, E.

    1996-01-01

    This paper presents an integrated radiation monitoring system designed to assess the effects of nuclear accidents and to provide a basis for making right decisions and countermeasures in order to reduce health damages. The system implies a number of stationary monitoring equipment, data processing unit and a communication network. The system meets the demands of efficiency and reliability, providing the needed tools to easily create programs able to process simple input data filling the information management system. (author). 10 refs

  2. Radiation damage to DNA: the effect of LET

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J F; Milligan, J R [California Univ., San Diego, La Jolla, CA (United States). School of Medicine

    1997-03-01

    Mechanisms whereby ionizing radiation induced damage are introduced into cellular DNA are discussed. The types of lesions induced are summarized and the rationale is presented which supports the statement that radiation induced singly damaged sites are biologically unimportant. The conclusion that multiply damaged sites are critical is discussed and the mechanisms whereby such lesions are formed are presented. Structures of multiply damaged sites are summarized and problems which they present to cellular repair systems are discussed. Lastly the effects of linear energy transfer on the complexity of multiply damaged sites are surveyed and the consequences of this increased complexity are considered in terms of cell survival and mutation. (author)

  3. Biologically important radiation damage in DNA

    International Nuclear Information System (INIS)

    Ward, J.F.

    1994-01-01

    Most DNA damage by the hydroxyl radical is confined to the bases, and this base damage represents an important component of locally multiply demanded sites (LMOS). The yields of the major damaged bases have been determined by gas chromatography mass spectrometry. For our propose, it was necessary to convert a known fraction of these damaged bases to strand breaks and then assay these labile sites as the increase in strand break yield over the normally observed level. Three potential agents by which this strategy of conversion of base damage to strand break could be implemented were identified in the original application: 1, Sl nuclease; 2, piperidine; and 3, base damage specific enzymes

  4. Radiation damage in a high Ni weld

    International Nuclear Information System (INIS)

    Brumovsky, M.; Kytka, M.; Kopriva, R.

    2015-01-01

    WWER-1000 RPV weld metals are characterized by a high content of nickel, mostly about 1.7 mass % with content of manganese around 0.8 mass % with a very low copper content - about 0.05 mass %. In such material some late blooming phase effect should be observed during irradiation. Such typical weld material was irradiated in the experimental reactor LVR-15 in N RI Rez at the irradiation temperature 290 C degrees and at five neutron fluences from 1.5 to 9.5 *10 23 m -2 (E>1 MeV). Charpy V-notch impact tests, static fracture toughness tests, tensile and hardness measurement were performed to obtain effect of neutron fluence on radiation hardening as well as embrittlement. Neutron fluence dependences of all these property changes have monotonic character but with a high neutron embrittlement exponent around 0.8. Scanning electron microscope of fracture surfaces showed no or very small portion of intercrystalline fracture. Transmission electron microscopy was performed on specimens from all neutron fluences. Only low density of black-dot damage has been observed. It is assumed that most of defect are dislocation loops. The late blooming phase which may be observed from results of mechanical properties are probably below the resolution of the used JEM-2010, i.e. 1.5 nm. (authors)

  5. Chemistry of radiation damage to wire chambers

    International Nuclear Information System (INIS)

    Wise, J.

    1992-08-01

    Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF 4 /iC 4 H 10 gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF 4 -rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF 4 , acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF 4 /iC 4 H 10 gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C 2 H 6 . Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl 3 F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds

  6. Distributed hierarchical radiation monitoring system

    International Nuclear Information System (INIS)

    Barak, D.

    1985-01-01

    A solution to the problem of monitoring the radiation levels in and around a nuclear facility is presented in this paper. This is a private case of a large scale general purpose data acqisition system with high reliability, availability and short maintenance time. The physical layout of the detectors in the plant, and the strict control demands dictated a distributed and hierarchical system. The system is comprised of three levels, each level contains modules. Level one contains the Control modules which collects data from groups of detectors and executes emergency local control tasks. In level two are the Group controllers which concentrate data from the Control modules, and enable local display and communication. The system computer is in level three, enabling the plant operator to receive information from the detectors and execute control tasks. The described system was built and is operating successfully for about two years. (author)

  7. Radiation Damage in Electronic Memory Devices

    OpenAIRE

    Fetahović, Irfan; Pejović, Milić; Vujisić, Miloš

    2013-01-01

    This paper investigates the behavior of semiconductor memories exposed to radiation in order to establish their applicability in a radiation environment. The experimental procedure has been used to test radiation hardness of commercial semiconductor memories. Different types of memory chips have been exposed to indirect ionizing radiation by changing radiation dose intensity. The effect of direct ionizing radiation on semiconductor memory behavior has been analyzed by using Monte Carlo simula...

  8. Radiation damage measurements in room temperature semiconductor radiation detectors

    International Nuclear Information System (INIS)

    Franks, L.A.; Olsen, R.W.; James, R.B.; Brunett, B.A.; Walsh, D.S.; Doyle, B.L.; Vizkelethy, G.; Trombka, J.I.

    1998-01-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI 2 ) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 10 p/cm 2 and significant bulk leakage after 10 12 p/cm 2 . CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 x 10 9 p/cm 2 in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10 10 n/cm 2 , although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 x 10 10 α/cm 2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 x 10 9 α/cm 2 . CT detectors show resolution losses after fluences of 3 x 10 9 p/cm 2 at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 x 10 10 n/cm 2 . Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10 12 p/cm 2 and with 1.5 GeV protons at fluences up to 1.2 x 10 8 p/cm 2 . Neutron exposures at 8 MeV have been reported at fluences up to 10 15 n/cm 2 . No radiation damage was reported under these irradiation conditions

  9. Radiation damage and its repair in non-sporulating bacteria

    International Nuclear Information System (INIS)

    Moseley, B.E.B.

    1984-01-01

    A review is given of radiation damage and its repair in non-sporulating bacteria. The identification and measurement of radiation damage in the DNA of the bacteria after exposure to ultraviolet radiation and ionizing radiation is described. Measuring the extent of DNA repair and ways of isolating repair mutants are also described. The DNA repair mechanisms for UV-induced damage are discussed including photoreactivation repair, excision repair, post-replication recombination repair and induced error-prone repair. The DNA repair mechanisms for ionizing radiation damage are also discussed including the repair of both single and double-strand breaks. Other aspects discussed include the effects of growth, irradiation medium and recovery medium on survival, DNA repair in humans, the commercial use of UV and ionizing radiations and the future of ionizing irradiation as a food treatment process. (U.K.)

  10. Damage tolerance and structural monitoring for wind turbine blades

    DEFF Research Database (Denmark)

    McGugan, Malcolm; Pereira, Gilmar Ferreira; Sørensen, Bent F.

    2015-01-01

    The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will b......The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation...

  11. DNA Damage by Radiation in Tradescantia Leaf Cells

    International Nuclear Information System (INIS)

    Han, Min; Hyun, Kyung Man; Ryu, Tae Ho; Kim, Jin Kyu; Nili, Mohammad

    2010-01-01

    The comet assay is currently used in different areas of biological sciences to detect DNA damage. The comet assay, due to its simplicity, sensitivity and need of a few cells, is ideal as a short-term genotoxicity test. The comet assay can theoretically be applied to every type of eukaryotic cell, including plant cells. Plants are very useful as monitors of genetic effects caused by pollution in the atmosphere, water and soil. Tradescantia tests are very useful tools for screening the mutagenic potential in the environment. Experiments were conducted to study the genotoxic effects of ionizing radiations on the genome integrity, particularly of Tradescantia. The increasingly frequent use of Tradescantia as a sensitive environmental bioindicator of genotoxic effects. This study was designed to assess the genotoxicity of ionizing radiation using Tradescnatia-comet assay. The development of comet assay has enabled investigators to detect DNA damage at the levels of cells. To adapt this assay to plant cells, nuclei were directly obtained from Tradescantia leaf samples. A significant dose-dependent increase in the average tail moment values over the negative control was observed. Recently the adaptation of this technique to plant cells opens new possibilities for studies in variety area. The future applications of the comet assay could impact some other important areas, certainly, one of the limiting factors to its utility is the imagination of the investigator.

  12. DNA Damage by Radiation in Tradescantia Leaf Cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Min; Hyun, Kyung Man; Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute, Jeongeup (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2010-04-15

    The comet assay is currently used in different areas of biological sciences to detect DNA damage. The comet assay, due to its simplicity, sensitivity and need of a few cells, is ideal as a short-term genotoxicity test. The comet assay can theoretically be applied to every type of eukaryotic cell, including plant cells. Plants are very useful as monitors of genetic effects caused by pollution in the atmosphere, water and soil. Tradescantia tests are very useful tools for screening the mutagenic potential in the environment. Experiments were conducted to study the genotoxic effects of ionizing radiations on the genome integrity, particularly of Tradescantia. The increasingly frequent use of Tradescantia as a sensitive environmental bioindicator of genotoxic effects. This study was designed to assess the genotoxicity of ionizing radiation using Tradescnatia-comet assay. The development of comet assay has enabled investigators to detect DNA damage at the levels of cells. To adapt this assay to plant cells, nuclei were directly obtained from Tradescantia leaf samples. A significant dose-dependent increase in the average tail moment values over the negative control was observed. Recently the adaptation of this technique to plant cells opens new possibilities for studies in variety area. The future applications of the comet assay could impact some other important areas, certainly, one of the limiting factors to its utility is the imagination of the investigator.

  13. Fatigue damage monitoring of structural aluminum alloys

    Directory of Open Access Journals (Sweden)

    С.Р. Ігнатович

    2004-01-01

    Full Text Available  Results of the experiments directed on creation of a new tool method of fatigue damage diagnostics and an estimation of a residual life of aviation designs are presented. It is shown, that the defo rmation relief formed on a surface of cladding  layer of sheets of constructional alloys Д-16АТ, 2024-Т3, 7075-Т6  can be considered as the metal damage indicator  under cyclically repeating loadings.

  14. Effect of Mercuric Nitrate on Repair of Radiation-induced DNA Damage

    Energy Technology Data Exchange (ETDEWEB)

    Paneka, Agnieszka; Antonina, Cebulska Wasilewska [The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Han, Min; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2009-10-15

    High concentrations of mercury can cause serious damage to the nervous system, immune system, kidneys and liver in humans. And mercury is toxic to developing embryos because mercury ions can penetrate the blood.placenta barrier to reach the embryo. Studies from human monitoring of occupational exposure to mercury vapours have shown that mercury can alter the ability of lymphocytes to repair radiation-induced DNA damage. The aim of this in vitro study was to investigate, on the molecular and cytogenetic levels, the effect of exposure to mercury ions on the kinetics of the repair process of DNA damage induced by ionising radiation.

  15. Radiation Damage in Electronic Memory Devices

    Directory of Open Access Journals (Sweden)

    Irfan Fetahović

    2013-01-01

    Full Text Available This paper investigates the behavior of semiconductor memories exposed to radiation in order to establish their applicability in a radiation environment. The experimental procedure has been used to test radiation hardness of commercial semiconductor memories. Different types of memory chips have been exposed to indirect ionizing radiation by changing radiation dose intensity. The effect of direct ionizing radiation on semiconductor memory behavior has been analyzed by using Monte Carlo simulation method. Obtained results show that gamma radiation causes decrease in threshold voltage, being proportional to the absorbed dose of radiation. Monte Carlo simulations of radiation interaction with material proved to be significant and can be a good estimation tool in probing semiconductor memory behavior in radiation environment.

  16. Progress on clustered DNA damage in radiation research

    International Nuclear Information System (INIS)

    Yang Li'na; Zhang Hong; Di Cuixia; Zhang Qiuning; Wang Xiaohu

    2012-01-01

    Clustered DNA damage which caused by high LET heavy ion radiation can lead to mutation, tumorigenesis and apoptosis. Promoting apoptosis of cancer cells is always the basis of cancer treatment. Clustered DNA damage has been the hot topic in radiobiology. The detect method is diversity, but there is not a detail and complete protocol to analyze clustered DNA damage. In order to provide reference for clustered DNA damage in the radiotherapy study, the clustered DNA damage characteristics, the latest progresses on clustered DNA damage and the detecting methods are reviewed and discussed in detail in this paper. (authors)

  17. Radiation damage in the alkali halide crystals

    International Nuclear Information System (INIS)

    Diller, K.M.

    1975-10-01

    A general review is given of the experimental data on radiation damage in the alkali halide crystals. A report is presented of an experimental investigation of irradiation produced interstitial dislocation loops in NaCl. These loops are found to exhibit the usual growth and coarsening behaviour during thermal annealing which operates by a glide and self-climb mechanism. It is shown that the recombination of defects in these crystals is a two stage process, and that the loss of interstitials stabilized at the loops is caused by extrinsic vacancies. The theoretical techniques used in simulating point defects in ionic crystals are described. Shell model potentials are derived for all the alkali halide crystals by fitting to bulk crystal data. The fitting is supplemented by calculations of the repulsive second neighbour interactions using methods based on the simple electron gas model. The properties of intrinsic and substitutional impurity defects are calculated. The HADES computer program is used in all the defect calculations. Finally the report returns to the problems of irradiation produced interstitial defects. The properties of H centres are discussed; their structure, formation energies, trapping at impurities and dimerization. The structure, formation energies and mobility of the intermediate and final molecular defects are then discussed. The thermodynamics of interstitial loop formation is considered for all the alklai halide crystals. The nucleation of interstitial loops in NaCl and NaBr is discussed, and the recombination of interstitial and vacancy defects. The models are found to account for all the main features of the experimental data. (author)

  18. Radiation Damage Studies of Silicon Photomultipliers

    CERN Document Server

    Bohn, P; Hazen, E.; Heering, A.; Rohlf, J.; Freeman, J.; Los, Sergey V.; Cascio, E.; Kuleshov, S.; Musienko, Y.; Piemonte, C.

    2008-01-01

    We report on the measurement of the radiation hardness of silicon photomultipliers (SiPMs) manufactured by Fondazione Bruno Kessler in Italy (1 mm$^2$ and 6.2 mm$^2$), Center of Perspective Technology and Apparatus in Russia (1 mm$^2$ and 4.4 mm$^2$), and Hamamatsu Corporation in Japan (1 mm$^2$). The SiPMs were irradiated using a beam of 212 MeV protons at Massachusetts General Hospital, receiving fluences of up to $3 \\times 10^{10}$ protons per cm$^2$ with the SiPMs at operating voltage. Leakage currents were read continuously during the irradiation. The delivery of the protons was paused periodically to record scope traces in response to calibrated light pulses to monitor the gains, photon detection efficiencies, and dark counts of the SiPMs. The leakage current and dark noise are found to increase with fluence. Te leakage current is found to be proportional to the mean square deviation of the noise distribution, indicating the dark counts are due to increased random individual pixel activation, while SiPM...

  19. Biological rhythms for rehabilitation of radiation damage of population

    International Nuclear Information System (INIS)

    Goncharova, T.G.; Vasil'eva, G.S.; Efimov, M.L.

    1999-01-01

    Considerable disturbances in biological eurhythmycal structure of redoracu were discovered for people living in Borodulikha area of the Semipalatinsk test site. The deep desynchronise may result in a development of the cardiovascular, bronco-pulmonary, endocrine, oncologic, neuro psychic diseases. A method to correct the biological eurhythmycal structure was developed. Homeopathic doses of melatonin ('rhythm driver' managing the most regenerating and immune systems) and uthynol (promoting production of dehydroepiandrosterone of maternal prehormone of 27 hormones) were used to provide the general correction. The endocrine diseases are not practically subjected to the homeopathic correction. The sub correction was sometimes carried out after 5 months. The developed methods of rehabilitation of the radiation damages are unique, since they allow performing the homeopathic correction using the acupuncture monitoring

  20. Radiation damage to nucleoprotein complexes in macromolecular crystallography

    International Nuclear Information System (INIS)

    Bury, Charles; Garman, Elspeth F.; Ginn, Helen Mary; Ravelli, Raimond B. G.; Carmichael, Ian; Kneale, Geoff; McGeehan, John E.

    2015-01-01

    Quantitative X-ray induced radiation damage studies employing a model protein–DNA complex revealed a striking partition of damage sites. The DNA component was observed to be far more resistant to specific damage compared with the protein. Significant progress has been made in macromolecular crystallography over recent years in both the understanding and mitigation of X-ray induced radiation damage when collecting diffraction data from crystalline proteins. In contrast, despite the large field that is productively engaged in the study of radiation chemistry of nucleic acids, particularly of DNA, there are currently very few X-ray crystallographic studies on radiation damage mechanisms in nucleic acids. Quantitative comparison of damage to protein and DNA crystals separately is challenging, but many of the issues are circumvented by studying pre-formed biological nucleoprotein complexes where direct comparison of each component can be made under the same controlled conditions. Here a model protein–DNA complex C.Esp1396I is employed to investigate specific damage mechanisms for protein and DNA in a biologically relevant complex over a large dose range (2.07–44.63 MGy). In order to allow a quantitative analysis of radiation damage sites from a complex series of macromolecular diffraction data, a computational method has been developed that is generally applicable to the field. Typical specific damage was observed for both the protein on particular amino acids and for the DNA on, for example, the cleavage of base-sugar N 1 —C and sugar-phosphate C—O bonds. Strikingly the DNA component was determined to be far more resistant to specific damage than the protein for the investigated dose range. At low doses the protein was observed to be susceptible to radiation damage while the DNA was far more resistant, damage only being observed at significantly higher doses

  1. Structural damage monitoring of harbor caissons with interlocking condition

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae [Pukyong National Univ., Busan (Korea, Republic of)

    2012-12-15

    The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons.

  2. Structural damage monitoring of harbor caissons with interlocking condition

    International Nuclear Information System (INIS)

    Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae

    2012-01-01

    The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons

  3. Radiation monitoring - the role of local authorities

    International Nuclear Information System (INIS)

    Duggan, Michael

    1988-01-01

    Seven reports of papers given at a symposium on the role of local authorities in radiation monitoring are given. The main theme is concerned with radiation monitoring, how to interpret the information and how it should be disseminated. The individual experiences in the aftermath of the Chernobyl reactor accident are used to illustrate several of the papers. (U.K.)

  4. A unique radiation area monitoring system

    International Nuclear Information System (INIS)

    Murphy, P.C.; Allen, G.C.

    1978-01-01

    The Remote Area Monitoring Systems (RAMS) monitors four radiation areas with two independent systems in each area. Each system consists of power supplies, four ionization chambers, and four analog and digital circuits. The first system controls the warning beacons, horns, annunciation panel and interlocks. The second system presents a quantitative dose rate indication at the console and in the radiation area

  5. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.

    1994-03-01

    This report presents the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1993. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

  6. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1993-03-01

    This report present the results of the NRC Direct Radiation Monitoring Network for the fourth quarter of 1992. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program

  7. Radiation monitoring network of the Czech Republic

    International Nuclear Information System (INIS)

    Drabova, D.; Prouza, Z.; Malatova, I.; Bucina, I.

    1996-01-01

    Radiation Monitoring Network of the Czech Republic (RMN) was established after the Chernobyl accident. It consists of technical centers, laboratories and monitoring groups of State Office for Nuclear Safety, National Radiation Protection Institute, nuclear power plants, hydrometeorological service, army and Civil Defense, research institutes and other institutions. The structure of RMN, its basic components and responsible institutions are described. (author)

  8. Computer-controlled radiation monitoring system

    International Nuclear Information System (INIS)

    Homann, S.G.

    1994-01-01

    A computer-controlled radiation monitoring system was designed and installed at the Lawrence Livermore National Laboratory's Multiuser Tandem Laboratory (10 MV tandem accelerator from High Voltage Engineering Corporation). The system continuously monitors the photon and neutron radiation environment associated with the facility and automatically suspends accelerator operation if preset radiation levels are exceeded. The system has proved reliable real-time radiation monitoring over the past five years, and has been a valuable tool for maintaining personnel exposure as low as reasonably achievable

  9. A new-generation radiation monitoring vehicle

    International Nuclear Information System (INIS)

    Gryc, Lubomir; Cespirova, Irena; Sury, Jan; Hanak, Vitezslav; Sladek, Petr

    2015-01-01

    A new radiation monitoring vehicle has been developed within the MOSTAR (Mobile and Stationary Radiation monitoring systems for a new generation of radiation monitoring network) Security Research project. The vehicle accommodates a system for radiation survey using scintillation detectors. Basic spectroscopy is performed with a sodium iodine crystal system, directional measurement is based on two side-mounted plastic detectors, logging dose rates, GPS coordinates and displaying results in a map. A semiconductor spectrometric chain for rapid qualitative and quantitative evaluation of environmental samples is also included. (orig.)

  10. Thermal annealing of natural, radiation-damaged pyrochlore

    Energy Technology Data Exchange (ETDEWEB)

    Zietlow, Peter; Beirau, Tobias; Mihailova, Boriana; Groat, Lee A.; Chudy, Thomas; Shelyug, Anna; Navrotsky, Alexandra; Ewing, Rodney C.; Schlüter, Jochen; Škoda, Radek; Bismayer, Ulrich

    2017-01-01

    Abstract

    Radiation damage in minerals is caused by the α-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400–1000 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia [6.4 wt% Th, 23.1·10

  11. Radiation damage for the spallation target of ADS

    International Nuclear Information System (INIS)

    Fan Sheng; Ye Yanlin; Xu Chuncheng; Chen Tao; Sobolevsky, N.M.

    2000-01-01

    By using SHIELD codes system, the authors investigate the radiation damage, such as radiation damage cross section, displacement atom cross section and the rate of displacement atom, gas production cross section, the rate of gas production and the ratio, R, of the helium and displacement production rates in target, container window and spallation neutron source materials as W and Pb induced from intermediate energy proton and neutron incident. And the study of radiation damage in the thick Pb target with long 60 cm, radius 20 cm is presented

  12. Radiation dose monitoring in the clinical routine

    Energy Technology Data Exchange (ETDEWEB)

    Guberina, Nika [UK Essen (Germany). Radiology

    2017-04-15

    Here we describe the first clinical experiences regarding the use of an automated radiation dose management software to monitor the radiation dose of patients during routine examinations. Many software solutions for monitoring radiation dose have emerged in the last decade. The continuous progress in radiological techniques, new scan features, scanner generations and protocols are the primary challenge for radiation dose monitoring software systems. To simulate valid dose calculations, radiation dose monitoring systems have to follow current trends and stay constantly up-to-date. The dose management software is connected to all devices at our institute and conducts automatic data acquisition and radiation dose calculation. The system incorporates 18 virtual phantoms based on the Cristy phantom family, estimating doses in newborns to adults. Dose calculation relies on a Monte Carlo simulation engine. Our first practical experiences demonstrate that the software is capable of dose estimation in the clinical routine. Its implementation and use have some limitations that can be overcome. The software is promising and allows assessment of radiation doses, like organ and effective doses according to ICRP 60 and ICRP 103, patient radiation dose history and cumulative radiation doses. Furthermore, we are able to determine local diagnostic reference doses. The radiation dose monitoring software systems can facilitate networking between hospitals and radiological departments, thus refining radiation doses and implementing reference doses at substantially lower levels.

  13. Fundamental Technology Development for Radiation Damage in Nuclear Materials

    International Nuclear Information System (INIS)

    Kwon, Sang Chul; Kwon, J. H.; Kim, E. S. and others

    2005-04-01

    This project was performed to achieve technologies for the evaluation of radiation effects at materials irradiated at HANARO and nuclear power plants, to establish measurement equipment and software for the analysis of radiation defects and to set up facilities for the measurements of radiation damage with non-destructive methods. Major targets were 1) establishment of hot laboratories and remote handling facilities/ technologies for the radioactive material tests, 2) irradiation test for the simulation of nuclear power plant environment and measurement/calculation of physical radiation damage, 3) evaluation and analysis of nano-scale radiation damage, 4) evaluation of radiation embrittlement with ultrasonic resonance spectrum measurement and electromagnetic measurement and 5) basic research of radiation embrittlement and radiation damage mechanism. Through the performance of 3 years, preliminary basics were established for the application research to evaluation of irradiated materials of present nuclear power plants and GEN-IV systems. Particularly the results of SANS, PAS and TEM analyses were the first output in Korea. And computer simulations of radiation damage were tried for the first time in Korea. The technologies will be developed for the design of GEN-IV material

  14. Photobiological aspects of radiation damage to bacteria

    International Nuclear Information System (INIS)

    Myasnik, M.N.; Skvortsov, V.G.; Sokolov, V.A.

    1981-01-01

    In this report, we, submit a critical analysis of experiments aimed to estimate the contribution of the processes of ionization and electron excitation to lethal and mutagenic effects of ionizing radiation. In discussing the phenomenon of photoreactivation after the effect of ionizing radiation, we arrived at a conclusion that the processes of electron excitation, initiated by either Vavilov-Cerenkov light or the direct reaction of radiation energy with the substance, play an important role in the biological effect of ionizing radiation [ru

  15. Damage tolerance and structural monitoring for wind turbine blades.

    Science.gov (United States)

    McGugan, M; Pereira, G; Sørensen, B F; Toftegaard, H; Branner, K

    2015-02-28

    The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques and modelling to manage the life cycle of the structures. This will allow an efficient operation of the wind turbine in terms of load alleviation, limited maintenance and repair leading to a more effective exploitation of offshore wind. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  16. Radiation damage measurements in room-temperature semiconductor radiation detectors

    CERN Document Server

    Franks, L A; Olsen, R W; Walsh, D S; Vizkelethy, G; Trombka, J I; Doyle, B L; James, R B

    1999-01-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI sub 2) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 sup 1 sup 0 p/cm sup 2 and significant bulk leakage after 10 sup 1 sup 2 p/cm sup 2. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5x10 sup 9 p/cm sup 2 in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from a moderated fission spectrum of neutrons after fluences up to 10 sup 1 sup 0 n/cm sup 2 , although activation was evident. Exposures of CZT to 5 MeV alpha particles at fluences up to 1.5x10 sup 1 sup 0 alpha/cm sup 2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5x10 sup 9 alpha/cm sup 2. CT detectors show resolution...

  17. Activation and radiation damage in the environment of hadron accelerators

    CERN Document Server

    Kiselev, Daniela

    2013-01-01

    A component which suffers radiation damage usually also becomes radioactive, since the source of activation and radiation damage is the interaction of the material with particles from an accelerator or with reaction products. However, the underlying mechanisms of the two phenomena are different. These mechanisms are described here. Activation and radiation damage can have far-reaching consequences. Components such as targets, collimators, and beam dumps are the first candidates for failure as a result of radiation damage. This means that they have to be replaced or repaired. This takes time, during which personnel accumulate dose. If the dose to personnel at work would exceed permitted limits, remote handling becomes necessary. The remaining material has to be disposed of as radioactive waste, for which an elaborate procedure acceptable to the authorities is required. One of the requirements of the authorities is a complete nuclide inventory. The methods used for calculation of such inventories are presented,...

  18. High LET radiation and mechanism of DNA damage repair

    International Nuclear Information System (INIS)

    Furusawa, Yoshiya

    2004-01-01

    Clarifying the mechanism of repair from radiation damage gives most important information on radiation effects on cells. Approximately 10% of biological experiments groups in Heavy Ion Medical Accelerator in Chiba (HIMAC) cooperative research group has performed the subject. They gave a lot of new findings on the mechanism, and solved some open questions. The reason to show the peak of relative biological effectiveness RBE at around 100-200 keV/μm causes miss-repair of DNA damage. Sub-lethal damage generated by high linear energy transfer (LET) radiation can be repaired fully. Potentially lethal damages by high-LET radiation also repaired, but the efficiency decreased with the LET, and so on. (author)

  19. Positron annihilation and perturbed angular correlation studies of radiation damage

    International Nuclear Information System (INIS)

    Zhu Jiazheng; Li Anli; Xu Yongjun; Wang Zhiqiang; Zhou Dongmei; Zheng Yongnan; Zhu Shengyun; Iwata, T.

    2002-01-01

    The positron annihilation and perturbed angular correlation techniques have been employed to study radiation damage in Si and Nb. The results obtained by the positron annihilation are consistent with those given by the perturbed angular correlation

  20. Single Molecule Scanning of DNA Radiation Oxidative Damage, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal will develop an assay to map genomic DNA, at the single molecule level and in a nanodevice, for oxidative DNA damage arising from radiation exposure;...

  1. Centralized environmental radiation monitoring system in JAERI

    International Nuclear Information System (INIS)

    Katagiri, Hiroshi; Kobayashi, Hideo

    1993-03-01

    Japan Atomic Energy Research Institute (JAERI) has continued the radiation background survey and environmental radiation monitoring to ensure the safety of the residents around the Institute. For the monitoring of β and γ radiations and α and β radioactivities in air, the centralized automatic environmental radiation monitoring system (EMS) applying a computer with monitoring stations (MS) was established. The system has been renewed twice in 1973 and 1988. In 1962, a new concept emergency environmental γ-ray monitoring system (MP) was begun to construct and completed in 1965 independent of EMS. The first renewal of the EMS was carried out by focusing on the rapid and synthetic judgement and estimation of the environmental impacts caused by radiation and radioactive materials due to the operation of nuclear facilities by centralizing the data measured at MS, MP, a meteorological station, stack monitors and drainage monitoring stations under the control of computer. Present system renewed in 1988 was designed to prevent the interruption of monitoring due to computer troubles, communication troubles and power failures especially an instant voltage drop caused by thunder by reflecting the experiences through the operation and maintenance of the former system. Dual telemeters whose power is constantly supplied via batteries (capable of 10 min. monitoring after power failure) are equipped in the monitoring center to cope with telemeter troubles, which has operated successfully without any suspension being attributable to the power failures and telemeter troubles. (J.P.N.)

  2. Radiation damage to the brain: neuropsychiatric aspects

    International Nuclear Information System (INIS)

    McMahon, T.; Vahora, S.

    1986-01-01

    Although radiation necrosis of the brain is a recognized complication of irradiation of the central nervous system, the psychiatric aspects of this phenomenon are less well defined. Two cases of radiation necrosis in which psychiatric symptoms were a prominent part of the clinical picture are presented. Factors that determine the evolution and clinical presentation of radiation necrosis are reviewed. In particular, the role of the consultation psychiatrist in the diagnosis and management of such patients is discussed

  3. Automated analysis of damages for radiation in plastics surfaces

    International Nuclear Information System (INIS)

    Andrade, C.; Camacho M, E.; Tavera, L.; Balcazar, M.

    1990-02-01

    Analysis of damages done by the radiation in a polymer characterized by optic properties of polished surfaces, of uniformity and chemical resistance that the acrylic; resistant until the 150 centigrade grades of temperature, and with an approximate weight of half of the glass. An objective of this work is the development of a method that analyze in automated form the superficial damages induced by radiation in plastic materials means an images analyst. (Author)

  4. Macroscopic morphology of radiation damage in copper

    International Nuclear Information System (INIS)

    Black, K.E.

    1977-01-01

    This Thesis describes the damage produced in copper single crystals when they are irradiated with neutrons from a nuclear reactor, and shows that the morphology of the damage is dependent on the temperature of irradiation. The production of point defects in the initial stages of the bombardment and their subsequent diffusion is described in Chapter One. Chapter Two describes the techniques used to etch and thus make visible the damage regions. The defect clusters were examined with a microscope. A typical selection of micrographs of the damage is presented and discussed in Chapter Three. In the final chapter, Chapter Four, the results of the present work are discussed in the light of work done by other research workers. The Thesis ends with a brief suggestion for future work to be carried out on neutron irradiated copper single crystals

  5. Biological monitoring of radiation using indicator plants

    International Nuclear Information System (INIS)

    Kim, Jin Kyoo; Chun, Ki Jung; Kim, Kook Chan; Kim, In Kyoo; Song, Heui Sub

    1994-12-01

    Some clones of Tradescantia had dose response relationship involving somatic mutations such as appearance of pink, colorless or giant cell, and/or loss of reproductive integrity of stamen hair cells when exposed to radiation. Since Tradescantia could respond to radiation level as low as human being could be exposed to, it could play an important role as scientific tool of botanical tester for radiation. Especially TSH system can be easily applied to in situ monitoring of radiation by virtue of its excellent radiation indicator ship and simpleness in detection of mutations by radiation. 10 figs, 6 tabs, 19 refs. (Author)

  6. Monitoring and crisis system of radiation safety

    International Nuclear Information System (INIS)

    Bartok, J.; Borovansky, P.; Macica, J.; Petrovicova, M.

    2005-01-01

    In this paper we have briefly described our practical experiences with the most complex Radiation Monitoring System we have designed. This system consists of number of stations; those data are collected in the main crisis center of the whole system. The main center integrates RMS Central Database, the IMS Model Suite workstation and the Graphics workstation. The radiations probes of the RP series are the base for stationary , portable sets and for sets measuring underwater radiation. The radiation and meteorological data, which are necessary for reasonable interpretation of radiation data, are archived in RMS Central database. The Lagrangian trajectory model from the IMS Model Suite serves for radiation dispersion modeling. (authors)

  7. Biological monitoring of radiation using indicator plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyoo; Chun, Ki Jung; Kim, Kook Chan; Kim, In Kyoo; Song, Heui Sub [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-12-01

    Some clones of Tradescantia had dose response relationship involving somatic mutations such as appearance of pink, colorless or giant cell, and/or loss of reproductive integrity of stamen hair cells when exposed to radiation. Since Tradescantia could respond to radiation level as low as human being could be exposed to, it could play an important role as scientific tool of botanical tester for radiation. Especially TSH system can be easily applied to in situ monitoring of radiation by virtue of its excellent radiation indicator ship and simpleness in detection of mutations by radiation. 10 figs, 6 tabs, 19 refs. (Author).

  8. Investigation of radiation damage effects in neutron irradiated CCD

    International Nuclear Information System (INIS)

    Brau, James E.; Igonkina, Olga; Potter, Chris T.; Sinev, Nikolai B.

    2005-01-01

    A Charge Coupled Devices (CCD)-based vertex detector is a leading option for vertex detection at the future linear collider. A major issue for this application is the radiation hardness of such devices. Tests of radiation hardness of CCDs used in the SLD vertex detector, VXD3, have been reported earlier. The first measurements of 1998 involved a spare VXD3 CCD that was irradiated with neutrons from a radioactive source (Pu-Be), and from a nuclear reactor. In 2003, we had the opportunity to disassemble the VXD3 detector and study the nature of the radiation damage it incurred during 3 years of operation at SLC. In the preparation for this study, additional experiments with the spare VXD3 CCD were performed. These included measurements of trapping times in neutron irradiated CCDs. Results, reported here, will help us better understand the mechanism of radiation damage effects and develop techniques to minimize performance degradation due to radiation damage

  9. Radiation damage to DNA: The importance of track structure

    CERN Document Server

    Hill, M A

    1999-01-01

    A wide variety of biological effects are induced by ionizing radiation, from cell death to mutations and carcinogenesis. The biological effectiveness is found to vary not only with the absorbed dose but also with the type of radiation and its energy, i.e., with the nature of radiation tracks. An overview is presented of some of the biological experiments using different qualities of radiation, which when compared with Monte Carlo track structure studies, have highlighted the importance of the localized spatial properties of stochastic energy deposition on the nanometer scale at or near DNA. The track structure leads to clustering of damage which may include DNA breaks, base damage etc., the complexity of the cluster and therefore its biological repairability varying with radiation type. The ability of individual tracks to produce clustered damage, and the subsequent biological response are important in the assessment of the risk associated with low-level human exposure. Recent experiments have also shown that...

  10. A review on radiation damage of erythrocyte membranes

    International Nuclear Information System (INIS)

    Wang Junling; Wang Weidong; Qin Guangyong

    2007-01-01

    Biomembrane has very important biological function. Its damage will seriously disturb the directivity, the orderly nature and coordination of cell metabolism, and finally causes the cell death. This paper reviewed the effects of radiation damage on erythrocyte membrane in membrane composition, membrane function and oxidation resistance system. (authors)

  11. Hydration-annealing of chemical radiation damage in calcium nitrate

    International Nuclear Information System (INIS)

    Nair, S.M.K.; James, C.

    1984-01-01

    The effect of hydration on the annealing of chemical radiation damage in anhydrous calcium nitrate has been investigated. Rehydration of the anhydrous irradiated nitrate induces direct recovery of the damage. The rehydrated salt is susceptible to thermal annealing but the extent of annealing is small compared to that in the anhydrous salt. The direct recovery of damage on rehydration is due to enhanced lattice mobility. The recovery process is unimolecular. (author)

  12. Centralized environmental radiation monitoring system in JAERI

    International Nuclear Information System (INIS)

    Katagiri, H.; Kobalyashi, H.

    1993-01-01

    JAERI has continued the environmental radiation background survey and monitoring to ensure the safety of the peoples around the institute since one year before the first criticality of JRR-1 (Japan Research Reactor No.1) in August 1957. Air absorbed doses from β and γ radiation, α and β radioactivity in air and the radioactivities in environmental samples were the monitoring items. For the monitoring of β and γ radiation and α and β radioactivity in air, monitoring station and the centralized automatic environmental radiation monitoring system applying a computer were established as a new challenging monitoring system for nuclear facility, which was the first one not only in Japan but also in the would in 1960 and since then the system has been renewed two times (in 1973 and 1988) by introducing the latest technology in the fields of radiation detection and computer control at each stage. Present system renewed in 1988 was designed to prevent the interruption of monitoring due to computer troubles, communication troubles and power failures especially an instant voltage drop arisen from thunder by reflecting the experiences through the operation and maintenance of the former system. Dual telemeters whose power is constantly supplied via batteries (capable of 10 min monitoring after power failure) are equipped in the monitoring center to cope with telemeter troubles, which has operated successfully without any suspension being attributable to the power failures and telemeter troubles

  13. Distributed Radiation Monitoring System for Linear Accelerators based on CAN Bus

    CERN Document Server

    Kozak, T; Napieralski, A

    2010-01-01

    Abstract—Gamma and neutron radiation is produced during the normal operation of linear accelerators like Free-Electron Laser in Hamburg (FLASH) or X-ray Free Electron Laser (X-FEL). Gamma radiation cause general degeneration of electronics devices and neutron fluence can be a reason of soft error in memories and microcontrollers. X-FEL accelerator will be built only in one tunnel, therefore most of electronic control systems will be placed in radiation environment. Exposing control systems to radiation may lead to many errors and unexpected failure of the whole accelerator system. Thus, the radiation monitoring system able to monitor radiation doses produced near controlling systems is crucial. Knowledge of produced radiation doses allows to detect errors caused by radiation, make plans of essential exchange of control systems and prevent accelerator from serious damages. The paper presents the project of radiation monitoring system able to monitor radiation environment in real time.

  14. Cytogenetic techniques as biological indicator and dosimeter of radiation damage

    International Nuclear Information System (INIS)

    Hadjidekova, V.; Hristova, R.

    2006-01-01

    Full text: The cytogenetic methods are established techniques for bio monitoring and bio dosimetry of professionally and accidentally exposed to ionizing radiation subjects. They are applied to continue the evaluation of the physical dosimetry and to consider the individual radiosensitivity. The results of cytogenetic monitoring and dosimetry of radiation exposed subjects carried out during the last 5 years in laboratory of Radiation Genetics, NCRRP is reported. Laboratory of Radiation genetics performs cytogenetic monitoring of low dose radiation professionally or medically exposed subjects: workers in Kozloduy NPP, radioactive waste repository workers, X-rays diagnostically exposed patients, and radiotherapy exposed as well. Three cytogenetic indicators are applied as the most sensitive indicators for human radiation exposure: analysis of micronuclei (MN), chromosomal aberrations (CA) and stable translocations (FISH). The optimized methodology for application of different cytogenetic techniques for radiation estimation is discussed

  15. Radiation-induced brain damage in children

    International Nuclear Information System (INIS)

    Oi, Shizuo; Kokunai, Takashi; Ijichi, Akihiro; Matsumoto, Satoshi; Raimondi, A.J.

    1990-01-01

    The nature and sequence of the radiation-induced changes in the brain were studied postmortem in 34 children with glioma, 22 of whom underwent central nervous system radiation therapy. Twenty received whole-brain or whole-neuroaxis radiation at a total mean dosage of 4063 cGy. Brain tissue alternations were analyzed histologically by means of various staining methods, including immunohistochemical techniques. The histological features of irradiated brains were compared with those of non-irradiated brains. Microscopic findings included demyelination (seven cases), focal necrosis (six cases), cortical atrophy (four cases), endothelial proliferation (four cases), and telangiectatic vascular proliferation with vascular thickening and oozing of a thick fluid (one case). Such findings were rare in non-irradiated patients. Demyelination was observed earliest in a patient who died 5 months after radiation therapy and was more common after 9 months. Focal necrosis was first observed 9 months post-irradiation but was more advanced and extensive after 1 year. Calcified foci were found only after 60 months. Various vascular changes such as vascular thickening and thrombosis suggested ischemic insult to the brain as a late effect of radiation injury. The results of this study suggest that the immature brain may be more sensitive to radiation than is the adult brain, and that the manifestations of radiation-induced injury depend on the time elapsed after irradiation. (author)

  16. Development of fusion first-wall radiation damage facilities

    International Nuclear Information System (INIS)

    McElroy, R.J.; Atkins, T.

    1986-11-01

    The report describes work performed on the development of fusion-reactor first-wall simulation facilities on the Variable Energy Cyclotron, at Harwell, United Kingdom. Two irradiation facilities have been constructed: i) a device for helium and hydrogen filling up to 1000 ppm for post-irradiation mechanical properties studies, and ii) a helium implantation and damage facility for simultaneous injection of helium and radiation damage into a specimen under stress. These facilities are now fully commissioned and are available for investigations of first-wall radiation damage and for intercorrelation of fission- and fusion -reactor materials behaviour. (U.K.)

  17. Chemical aspects of radiation damage processes: radiolysis

    International Nuclear Information System (INIS)

    Asmus, K.D.

    1975-01-01

    The formation of primary species and radiation chemical yields are discussed. In a section on chemical scavenging of primary species the author considers scavenging kinetics and competition reactions and gives a brief outline of some experimental methods. The radiation chemistry of aqueous solutions is discussed as an example for polar solvents. Cyclohexane is used as an example for non-polar solvents. The importance of excited states and energy transfer is considered. Reactions in the solid state are discussed and results on linear energy transfer and average ion pair formation for various kinds of radiation are surveyed. (B.R.H.)

  18. Radiation damage in molybdenum and tungsten in high neutron fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Veljkovic, S; Milasin, N [Institute of Nuclear Sciences Boris Kidric, Department of Reactor Materials, Vinca, Beograd (Serbia and Montenegro)

    1964-04-15

    The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

  19. Early mechanisms in radiation-induced biological damage

    International Nuclear Information System (INIS)

    Powers, E.L.

    1983-01-01

    An introduction to the mechanisms of radiation action in biological systems is presented. Several questions about the nature of the radiation damage process are discussed, including recognition of the oxygen effects, dose-response relationships, and the importance of the hydroxyl radical

  20. Radiation damage in molybdenum and tungsten in high neutron fluxes

    International Nuclear Information System (INIS)

    Veljkovic, S.; Milasin, N.

    1964-01-01

    The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

  1. Issues of damage estimation under radiation emergency situation

    International Nuclear Information System (INIS)

    Volobuev, P.V.; Kozlova, N.I.

    2005-01-01

    The specificity of social, economical and ecological consequences of major radiation emergency situation is considered in the paper. The definitions and structure of direct and indirect damage under radiation emergency situation are given. The priority components of immediate expenses and those of long-term living on the contaminated territories are considered in the paper. (author)

  2. Radiation damage calculations for compound materials

    International Nuclear Information System (INIS)

    Greenwood, L.R.

    1990-01-01

    This paper reports on the SPECOMP computer code, developed to calculate neutron-induced displacement damage cross sections for compound materials such as alloys, insulators, and ceramic tritium breeders for fusion reactors. These new calculations rely on recoil atom energy distributions previously computed with the DISCS computer code, the results of which are stored in SPECTER computer code master libraries. All reaction channels were considered in the DISCS calculations and the neutron cross sections were taken from ENDF/B-V. Compound damage calculations with SPECOMP thus do not need to perform any recoil atom calculations and consequently need no access to ENDF or other neutron data bases. The calculations proceed by determining secondary displacements for each combination of recoil atom and matrix atom using the Lindhard partition of the recoil energy to establish the damage energy

  3. Radiation damage calculations for compound materials

    International Nuclear Information System (INIS)

    Greenwood, L.R.

    1989-01-01

    Displacement damage calculations can be performed for 40 elements in the energy range up to 20 MeV with the SPECTER computer code. A recent addition to the code, called SPECOMP, can intermix atomic recoil energy distributions for any four elements to calculate the proper displacement damage for compound materials. The calculations take advantage of the atomic recoil data in the SPECTER libraries, which were determined by the DISCS computer code, using evaluated neutron cross section and angular distribution data in ENDF/B-V. Resultant damage cross sections for any compound can be added to the SPECTER libraries for the routine calculation of displacements in any given neutron field. Users do not require access to neutron cross section files. Results are presented for a variety of fusion materials and a new ceramic superconductor material. Future plans and nuclear data needs are discussed. 11 refs., 6 figs., 1 tab

  4. Conformational variation of proteins at room temperature is not dominated by radiation damage

    International Nuclear Information System (INIS)

    Russi, Silvia; González, Ana; Kenner, Lillian R.; Keedy, Daniel A.; Fraser, James S.; Bedem, Henry van den

    2017-01-01

    Protein crystallography data collection at synchrotrons is routinely carried out at cryogenic temperatures to mitigate radiation damage. Although damage still takes place at 100 K and below, the immobilization of free radicals increases the lifetime of the crystals by approximately 100-fold. Recent studies have shown that flash-cooling decreases the heterogeneity of the conformational ensemble and can hide important functional mechanisms from observation. These discoveries have motivated increasing numbers of experiments to be carried out at room temperature. However, the trade-offs between increased risk of radiation damage and increased observation of alternative conformations at room temperature relative to cryogenic temperature have not been examined. A considerable amount of effort has previously been spent studying radiation damage at cryo-temperatures, but the relevance of these studies to room temperature diffraction is not well understood. Here, the effects of radiation damage on the conformational landscapes of three different proteins (T. danielli thaumatin, hen egg-white lysozyme and human cyclophilin A) at room (278 K) and cryogenic (100 K) temperatures are investigated. Increasingly damaged datasets were collected at each temperature, up to a maximum dose of the order of 10 7 Gy at 100 K and 10 5 Gy at 278 K. Although it was not possible to discern a clear trend between damage and multiple conformations at either temperature, it was observed that disorder, monitored by B-factor-dependent crystallographic order parameters, increased with higher absorbed dose for the three proteins at 100 K. At 278 K, however, the total increase in this disorder was only statistically significant for thaumatin. A correlation between specific radiation damage affecting side chains and the amount of disorder was not observed. Lastly, this analysis suggests that elevated conformational heterogeneity in crystal structures at room temperature is observed despite radiation

  5. Molecular mechanisms in radiation damage to DNA. Progress report

    International Nuclear Information System (INIS)

    Osman, R.

    1994-01-01

    The objectives of this work are to elucidate the molecular mechanisms that are responsible for radiation-induced DNA damage. The overall goal is to understand the relationship between the chemical and structural changes produced by ionizing radiation in DNA and the resulting impairment of biological function expressed as carcinogenesis or cell death. The studies are based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA. These mechanistic explorations should lead to the formulation of testable hypotheses regarding the processes of impairment of regulation of gene expression, alteration in DNA repair, and damage to DNA structure involved in cell death or cancer

  6. The role of radiation damage analysis in the fusion program

    International Nuclear Information System (INIS)

    Doran, D.G.

    1983-01-01

    The objective of radiation damage analysis is the prediction of the performance of facility components exposed to a radiation environment. The US Magnetic Fusion Energy materials program includes an explicit damage analysis activity within the Damage Analysis and Fundamental Studies (DAFS) Program. Many of the papers in these Proceedings report work done directly or indirectly in support of the DAFS program. The emphasis of this program is on developing procedures, based on an understanding of damage mechanisms, for applying data obtained in diverse radiation environments to the prediction of component behavior in fusion devices. It is assumed that the Fusion Materials Irradiation Test Facility will be available in the late 1980s to test (and calibrate where necessary) correlation procedures to the high fluences expected in commercial reactors. (orig.)

  7. Radiation tolerance assurance of technical equipment in the LHC radiation monitoring for technical equipment at the LHC

    CERN Document Server

    Wijnands, Thijs; CERN. Geneva. TS Department

    2005-01-01

    In contrast with other accelerators at CERN, a large amount of technical equipment will be located in the LHC tunnel, the underground areas and in the experimental caverns where they will be exposed to radiation. Nearly all this equipment makes, to a certain extent, use of commercial microelectronics which is extremely sensitive to radiation damage, both instantaneous damage and cumulative damage. Examples in the TS Department are the electronics for the position sensors of the low beta quadrupoles, the access system, the cooling and ventilation units, the electronics for the electrical distribution, the oxygen deficiency monitors and fire detection systems. The basic effects of radiation on electronic systems and components are well understood because similar problems with radiation are encountered in the aerospace and aviation industry. Since 1998, an efficient and original Radiation Tolerance Assurance approach for the LHC machine has been established. Its aim is to minimise the effects of radiation damage...

  8. Federal Radiological Monitoring and Assessment Center Monitoring Manual Volume 2, Radiation Monitoring and Sampling

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Aerial Measurement Systems

    2012-07-31

    The FRMAC Monitoring and Sampling Manual, Volume 2 provides standard operating procedures (SOPs) for field radiation monitoring and sample collection activities that are performed by the Monitoring group during a FRMAC response to a radiological emergency.

  9. Radiation monitoring system based on EPICS

    International Nuclear Information System (INIS)

    Wang Weizhen; Li Jianmin; Wang Xiaobing; Hua Zhengdong; Xu Xunjiang

    2008-01-01

    Shanghai Synchrotron Radiation Facility (SSRF for short) is a third-generation light source building in China, including a 150 MeV injector, 3.5 GeV booster, 3.5 GeV storage ring and an amount of beam line stations. During operation, a mass of Synchrotron Radiation will be produced by electrons in the booster and the storage ring. Bremsstrahlung and neutrons will also be produced as a result of the interaction between the electrons, especially the beam loss, and the wall of the vacuum beam pipe. SSRF Radiation Monitoring System is established for monitoring the radiation dosage of working area and environment while SSRF operating. The system consists of detectors, intelligent data-collecting modules, monitoring computer, and managing computer. The software system is developed based on EPICS (Experimental Physics and Industrial Control System), implementing the collecting and monitoring the data output from intelligent modules, analyzing the data, and so on. (authors)

  10. Radiation monitor system for nuclear power plants

    International Nuclear Information System (INIS)

    Wu Bingzhe; Guo Shusheng

    1990-12-01

    The system has 8 kinds of radiation monitors and 2 stage microcomputers designed for processing the data from each monitor, storaging the information, printing out and displaying on the colour CRT. The function of the system includes high-value alarm, warm alarm and failure alarm, so called t hree-level alarms . Two functions of the alarms are the threshold alarm and the tendency alarm, so that this system is an intelligency system. This system has high reliability and very wide range when LOCA accident takes place. It is aseismic and immune to industrial interference. The system can meet IEC-761-1 standard and is of nuclear safety 3rd class. Also the following monitors were designed: 133 Xe monitor, 131 I monitor, low-level liquid monitor and high radiation γ area monitor. The system can meet the requirements of nuclear power plants

  11. State of damage of radiation facilities in great Hanshin earthquake

    International Nuclear Information System (INIS)

    1995-01-01

    The southern Hyogo Prefecture earthquake of magnitude 7.2 occurred in the early morning of January 17, 1995. The outline of the earthquake and dead and injured, the damages of buildings, life lines, roads, railways and harbors, liquefaction phenomena, the state of occurrence of fires and so on are reported. The districts where the earthquakes of magnitude 5 or stronger occurred, and the radiation facilities in those districts are shown. The state of damage of radiation facilities in past earthquakes is summarized. From January 17 to 19 after the earthquake, Science and Technology Agency gave necessary instruction to and heard the state of damage from 79 permitted facilities in the areas of magnitude 7 or 6 by telephone, and received the report that there was not the fear of radiation damage in all facilities. Also the state of damage of radiation facilities was investigated at the actual places, and the questionnaires on the state of radiation facilities and the action at the time of the earthquake were performed. The state of radiation facilities accompanying the earthquake is reported. The matters to be reflected to the countermeasures to earthquakes anew for the protection of facilities, communication system, facility checkup system and the resumption of use are pointed out. (K.I.)

  12. Environmental radiation monitoring of Vizag City

    International Nuclear Information System (INIS)

    Sreekanth, B.; Narsaiah, M.V.R.; Saindane, Shashank; Pujari, Raju; Krishna, N.S.; Sambamurthy, T.; Chaudhury, Probal; Pradeepkumar, K.S.

    2014-01-01

    Radiological impact assessment is to be carried out following any radiological emergency to implement the required counter measures. A ground based environmental radiation monitoring of Vizag city has been carried out by installing various radiation monitoring instruments in a vehicle to generate the base line radiation data. It also helps to check the illicit trafficking of radioactive sources and also identifying the orphan sources. The average background radiation level observed in Vizag city was 80 nGy/h. Database of baseline radiation level with GPS location at all important locations of the whole city has been developed. No illicit trafficking of radioactive materials and orphan sources were detected during the survey. All the detectors used in the survey shown good correlation in their response. The study showed that mobile monitoring methodology will be useful in the quick assessment of radiological impact and strengthens the decision makers in reducing consequences by initiating immediate counter measures

  13. Radiation Damage Observations in the ATLAS Pixel Detector Using the High Voltage Delivery System

    CERN Document Server

    Toms, K

    2011-01-01

    We describe the implementation of radiation damage monitoring using leakage current measurement of the silicon pixel sensors provided by the circuits of the ATLAS Pixel Detector high voltage delivery (HVPP4) system. The dependence of the leakage current upon the integrated luminosity for several temperature scenarios is presented. Based on the analysis we have determined the sensitivity specifications for a Current Measurement System. The status of the system and the first measurement of the radiation damage corresponding to 2--4 fb$^{-1}$ of integrated luminosity are presented, as well as the comparison with the theoretical model.

  14. Radiation Damage in Reactor Materials. Part of the Proceedings of the Symposium on Radiation Damage in Solids and Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-08-15

    Radiation damage has presented a new design parameter for the selection of materials to be used in fuel and cladding elements, moderators, structural components and pressure vessels in nuclear reactors. The severe and novel requirements for certain optimum combinations of physical and nuclear properties have emphasized the need for a better understanding of the basic mechanisms of radiation damage. This knowledge is not only essential for progress in the field of nuclear energy, but has direct applications to space technology and semi-conductor research as well. The IAEA, as part of its programme of promoting nuclear technology, therefore convened the Symposium on Radiation Damage in Solids and Reactor Materials, 7-11 May 1962. At the invitation of, and with generous material assistance from, the Government of Italy, the Symposium was held at Venice. The Symposium was primarily concerned with the investigation of the fundamental processes of radiation that underlie the behaviour of metals, alloys and ceramics that are actually useful or potentially useful reactor materials. Two sessions were devoted to studies of irradiation effects on simple metals, as these effects are easiest to interpret. Other topics included general theory, alloys, fissionable and moderator materials and special experimental techniques for radiation damage studies. The properties influenced by irradiation which were of main concern were those of primary importance to the behaviour of solids as reactor materials (e. g. dimensional stability, phase transformation, radiation hardening, fracture, fission-gas escape from uranium and its compounds). Other properties, such as optical, electrical and magnetic properties, and effects on semiconductors, ionic and other non-metallic crystals are also of interest in that these studies can increase our knowledge of the mechanism of radiation damage in solids and provide a tool for investigation into the physics of the solid state by offering a means of

  15. Radiation Damage in Reactor Materials. Part of the Proceedings of the Symposium on Radiation Damage in Solids and Reactor Materials

    International Nuclear Information System (INIS)

    1963-01-01

    Radiation damage has presented a new design parameter for the selection of materials to be used in fuel and cladding elements, moderators, structural components and pressure vessels in nuclear reactors. The severe and novel requirements for certain optimum combinations of physical and nuclear properties have emphasized the need for a better understanding of the basic mechanisms of radiation damage. This knowledge is not only essential for progress in the field of nuclear energy, but has direct applications to space technology and semi-conductor research as well. The IAEA, as part of its programme of promoting nuclear technology, therefore convened the Symposium on Radiation Damage in Solids and Reactor Materials, 7-11 May 1962. At the invitation of, and with generous material assistance from, the Government of Italy, the Symposium was held at Venice. The Symposium was primarily concerned with the investigation of the fundamental processes of radiation that underlie the behaviour of metals, alloys and ceramics that are actually useful or potentially useful reactor materials. Two sessions were devoted to studies of irradiation effects on simple metals, as these effects are easiest to interpret. Other topics included general theory, alloys, fissionable and moderator materials and special experimental techniques for radiation damage studies. The properties influenced by irradiation which were of main concern were those of primary importance to the behaviour of solids as reactor materials (e. g. dimensional stability, phase transformation, radiation hardening, fracture, fission-gas escape from uranium and its compounds). Other properties, such as optical, electrical and magnetic properties, and effects on semiconductors, ionic and other non-metallic crystals are also of interest in that these studies can increase our knowledge of the mechanism of radiation damage in solids and provide a tool for investigation into the physics of the solid state by offering a means of

  16. Introduction of neutron metrology for reactor radiation damage

    International Nuclear Information System (INIS)

    Alberman, A.; Genthon, J.P.; Schneider, W.; Wright, S.B.; Zijp, W.L.

    1979-01-01

    The background of the procedures for determining irradiation parameters which are of interest in radiation damage experiments is described. The first two chapters outline the concept of damage functions and damage models. The next two chapters give information on methods to determine neutron fluences and neutron spectra. The fifth chapter gives a review of correlation data available for graphite and steels. The last chapter gives guidance how to report the relevant irradiation parameters. Attention is given to the role of the neutron spectrum in deriving values for damage fluence, energy transferred to the lattice, and number of displacements

  17. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1991-04-01

    This report presents the results of the NRC [Nuclear Regulatory Commission] Direct Radiation Monitoring Network for the fourth quarter of 1990. It provides the ambient radiation levels measured in the vicinity of 75 sites throughout the United States. In addition, it describes the equipment used, monitoring station selection criteria, characterization of the dosimeter response, calibration procedures, statistical methods, intercomparison, and quality assurance program. 3 figs., 4 tabs

  18. Radiation damage testing at the SSC [Superconducting Super Collider

    International Nuclear Information System (INIS)

    Chinowsky, W.; Thun, R.

    1990-06-01

    A Task Force on Radiation Damage Testing met at the SSC Laboratory on March 5--6, 1990. This Task Force was asked to assess the availability of appropriate facilities for radiation damage tests of SSC detector materials and components. The Task Force was also instructed to review the techniques and standards for conducting such tests. Semiconductors were considered separately from other detector materials. Radiation damage test of electronic devices generally require exposures to both ionizing radiation and neutrons, whereas non-electric components such as plastic scintillating materials, adhesives, cable insulation, and other organic polymers are adequately tested with ionizing radiation only. Test standards are discussed with respect to irradiation techniques, environmental factors, dosimetry, and mechanisms whereby various materials are damaged. It is emphasized that radiation sources should be chosen to duplicate as much as possible the expected SSC environment and that the effects from ionizing particles and from neutrons be investigated separately. Radiation damage tests at reactors must be designed with particular care complex spectra of neutrons and gamma rays are produced at such facilities. It is also essential to investigate dose-rate effects since they are known to be important in many cases. The required irradiations may last several months and are most easily carried out with dedicated radioactive sources. Environmental factors such as the presence of oxygen when testing plastic scintillators, or temperature when measuring semiconductor annealing effects, must also be taken into account. The importance of reliable dosimetry is stressed and suitable references cited. Finally, it is noted that an understanding of the mechanisms for radiation damage in semiconductor and other materials is important in planning irradiations and evaluating results

  19. New approach to radiation monitoring: citizen based radiation measurement

    International Nuclear Information System (INIS)

    Kuca, P.; Helebrant, J.

    2016-01-01

    Both the Fukushima Dai-chi NPP accident in Japan in 2011 and the Chernobyl NPP accident in USSR in 1986 similarly to the first one have shown a necessity to find a way how to improve confidence of the public to official authorities. It is important especially in such a case of severe accidents with significant consequences in large inhabited areas around the damaged NPP. A lack of public confidence to officials was caused mostly by rather poor communication between official authorities and the public, as well by restricted access to the information for the public. It may have extremely negative impacts on the public understanding of actual situation and its possible risks, on public acceptance of necessary protective measures and participation of the public in remediation of the affected areas. One of possible ways to improve the situation can be implementation of citizen radiation monitoring on voluntary basis. Making sure, the official results are compatible with public self-measured ones, the public probably has more confidence in them. In the Czech Republic the implementation of such an approach is tested in the framework of security research founded by the Czech Ministry of the Interior - the research project RAMESIS solved by SURO. (authors)

  20. Environmental radiation monitoring around the nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Woo; Choi, Geun Sik and others

    2001-02-01

    Environmental Radiation Monitoring was carried out with measurement of environment. Radiation and environmental radioactivity analysis around KAERI nuclear facilities and Seoul Research Reactor. The results of environmental radiation monitoring around KAERI nuclear facilities and Seoul Research Reactor are the follows : The average level of environmental radiation dose measured by NaI scintillation counter and accumulated radiation dose by TLD was almost same level compared with the past years. Gross {alpha}, {beta} radioactivity in environmental samples showed a environmental level. {gamma}-radionuclides in water samples were not detected. But only radionuclide K-40, which is natural radionuclide, was detected in the all samples and Cs-137 was detected in the surface soil and discharge sediment. The average level of environmental radiation dose around Seoul Research Reactor was almost same level compared with the past years, and Be-7 and Cs-137 were detected in some surface soil and discharge sediment by {gamma}-spectrometry.

  1. Environmental radiation monitoring around the nuclear facilities

    International Nuclear Information System (INIS)

    Lee, Chang Woo; Choi, Young Ho

    2000-02-01

    Environmental radiation monitoring was carried out with measurement of environment radiation and environmental radioactivity analysis around KAERI nuclear facilities and Seoul Research Reactor. The results of environmental radiation monitoring around KAERI nuclear facilities and Seoul Research Reactor are the follows: The average level of environmental radiation dose measured by NaI scintillation counter and accumulated radiation dose by TLD was almost some level compared with the past years. Gross α, β radioactivity in environmental samples showed a environmental level. γ-radionuclides in water sample were not detected. But only radionuclide K-40, which is natural radionuclide, was detected in the all samples and Cs-137 was detected in the surface soil and discharge sediment. The average level of environmental radiation dose around Seoul Research Reactor was almost same level compared with the past years, and Be-7 and Cs-137 were detected in some surface soil and discharge sediment by γ-spectrometry. (author)

  2. Environmental radiation monitoring around the nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Woo; Choi, Young Ho

    2000-02-01

    Environmental radiation monitoring was carried out with measurement of environment radiation and environmental radioactivity analysis around KAERI nuclear facilities and Seoul Research Reactor. The results of environmental radiation monitoring around KAERI nuclear facilities and Seoul Research Reactor are the follows: The average level of environmental radiation dose measured by NaI scintillation counter and accumulated radiation dose by TLD was almost some level compared with the past years. Gross {alpha}, {beta} radioactivity in environmental samples showed a environmental level. {gamma}-radionuclides in water sample were not detected. But only radionuclide K-40, which is natural radionuclide, was detected in the all samples and Cs-137 was detected in the surface soil and discharge sediment. The average level of environmental radiation dose around Seoul Research Reactor was almost same level compared with the past years, and Be-7 and Cs-137 were detected in some surface soil and discharge sediment by {gamma}-spectrometry. (author)

  3. Environmental radiation monitoring around the nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Woo; Choi, Young Ho; Lee, M.H. [and others

    1999-02-01

    Environmental radiation monitoring was carried out with measurement of environment radiation and environmental radioactivity analysis around KAERI nuclear facilities and Seoul research reactor. The results of environmental radiation monitoring around KAERI nuclear facilities and Seoul research reactor are the follows : The average level of environmental radiation dose measured by NaI scintillation counter and accumulated radiation dose by TLD was almost same level compared with the past years. Gross {alpha}, {beta} radioactivity in environmental samples showed a environmental level. {gamma}-radionuclides in water samples were not detected. But only radionuclide K-40, which is natural radionuclide, was detected in the all samples and Cs-137 was detected in the surface soil and discharge sediment. The average level of environmental radiation dose around Seoul research reactor was almost same level compared with the past years, and Be-7 and Cs-137 were detected in some surface soil and discharge sediment by {gamma}-spectrometry. (author). 3 refs., 50 tabs., 12 figs.

  4. Environmental radiation monitoring around the nuclear facilities

    International Nuclear Information System (INIS)

    Lee, Chang Woo; Choi, Geun Sik and others

    2001-02-01

    Environmental Radiation Monitoring was carried out with measurement of environment. Radiation and environmental radioactivity analysis around KAERI nuclear facilities and Seoul Research Reactor. The results of environmental radiation monitoring around KAERI nuclear facilities and Seoul Research Reactor are the follows : The average level of environmental radiation dose measured by NaI scintillation counter and accumulated radiation dose by TLD was almost same level compared with the past years. Gross α, β radioactivity in environmental samples showed a environmental level. γ-radionuclides in water samples were not detected. But only radionuclide K-40, which is natural radionuclide, was detected in the all samples and Cs-137 was detected in the surface soil and discharge sediment. The average level of environmental radiation dose around Seoul Research Reactor was almost same level compared with the past years, and Be-7 and Cs-137 were detected in some surface soil and discharge sediment by γ-spectrometry

  5. Environmental radiation monitoring around the research reactors

    International Nuclear Information System (INIS)

    Lee, Chang Woo; Lee, Hyun Duk; Kim, Sam Rang; Choi, Yong Ho; Kim, Jeong Moo; Lee, Myeon Joo; Lee, Myeong Ho; Hong, Kwang Hee; Lim, Moon Ho; Lee, Won Yoon; Park, Do Won; Choi, Sang Do

    1993-04-01

    Environmental radiation monitoring was carried out measurement of environmental radiation and environmental radioactivity analysis around KAERI nuclear facilities and Seoul research reactor. The results of environmental radiation monitoring around KAERI nuclear facilities and Seoul research reactor are the follows : The average level of environmental radiation dose measured by NaI scintillation counter and accumulated radiation dose by TLD was almost same level compared with the past years. Gross α, β radioactivity in environmental sample was not found abnormal data. γ-radionuclides in water samples were not detected. But only radionuclide K-40, which is natural radionuclide, was detected in the all samples and Cs-137 was detected in the surface soil and discharge sediment. The average level of environmental radiation dose around Seoul research reactor was almost same level compared with the past years, and Be-7 and Cs-137 were detected in some surface soil and discharge sediment by γ-spectrometry. (Author)

  6. Monitoring Moisture Damage Propagation in GFRP Composites Using Carbon Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Sabagh

    2017-03-01

    Full Text Available Glass fiber reinforced polymer (GFRP composites are widely used in infrastructure applications including water structures due to their relatively high durability, high strength to weight ratio, and non-corrosiveness. Here we demonstrate the potential use of carbon nanoparticles dispersed during GFRP composite fabrication to reduce water absorption of GFRP and to enable monitoring of moisture damage propagation in GFRP composites. GFRP coupons incorporating 2.0 wt % carbon nanofibers (CNFs and 2.0 wt % multi-wall carbon nanotubes (MWCNTs were fabricated in order to study the effect of moisture damage on mechanical properties of GFRP. Water absorption tests were carried out by immersing the GFRP coupons in a seawater bath at two temperatures for a time period of three months. Effects of water immersion on the mechanical properties and glass transition temperature of GFRP were investigated. Furthermore, moisture damage in GFRP was monitored by measuring the electrical conductivity of the GFRP coupons. It was shown that carbon nanoparticles can provide a means of self-sensing that enables the monitoring of moisture damage in GFRP. Despite the success of the proposed technique, it might not be able to efficiently describe moisture damage propagation in GFRP beyond a specific threshold because of the relatively high electrical conductivity of seawater. Microstructural investigations using Fourier Transform Infrared (FTIR explained the significance of seawater immersion time and temperature on the different levels of moisture damage in GFRP.

  7. The Juno Radiation Monitoring (RM) Investigation

    DEFF Research Database (Denmark)

    Becker, H. N.; Alexander, J. W.; Adriani, A.

    2017-01-01

    The Radiation Monitoring Investigation of the Juno Mission will actively retrieve and analyze the noise signatures from penetrating radiation in the images of Juno’s star cameras and science instruments at Jupiter. The investigation’s objective is to profile Jupiter’s > 10-MeV electron environmen...

  8. Radiation damage in nuclear waste ceramics

    International Nuclear Information System (INIS)

    Turcotte, R.P.; Roberts, F.P.; Rusin, J.M.; Wald, J.W.

    1982-01-01

    The text contains a number of specific observations about the radiation-induced changes in glass, glass-ceramic, and supercalcine nuclear waste forms. Other, more general conclusions can be summarized: Radiation-induced property changes follow an exponential ingrowth curve to saturation. Actinide host phases in both crystalline waste forms become X-ray amorphous. The magnitudes of the waste-form density changes observed could not be directly related to observed changes in the primary actinide phases. Although large crystal-structure changes occur in the materials studied, obvious physical degradation was not observed

  9. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1992-06-01

    The US Nuclear Regulatory Commission (NRC) Direct Radiation Monitoring Network is operated by the NRC in cooperation with participating states to provide continuous measurement of the ambient radiation levels around licensed NRC facilities, primarily power reactors. Ambient radiation levels result from naturally occurring radionuclides present in the soil, cosmic radiation constantly bombarding the earth from outer space, and the contribution, if any, from the monitored facilities and other man-made sources. The Network is intended to measure radiation levels during routine facility operations and to establish background radiation levels used to assess the radiological impact of an unusual condition, such as an accident. This report presents the radiation levels measured around all facilities in the Network for the first quarter of 1992. All radiation measurements are made using small, passive detectors called thermoluminescent dosimeters (TLDs), which provide a quantitative measurement of the radiation levels in the area in which they are placed. Each site is monitored by arranging approximately 40 to 50 TLD stations in two concentric rings extending to about five miles from the facility. All TLD stations are outside the site boundary of the facility

  10. Radiation damage at the molecular level: Nanodosimetry

    International Nuclear Information System (INIS)

    Blanco, F.; Munoz, A.; Lagares, J. I.; Nunez, L.; Garcia, G.

    2013-01-01

    One of the main practical use of the model is its use as a tool of nanodosimetry which basically consists in characterizing the effect of radiation on nano volumes (comparable to the DNA of volumes) in terms of link breaks and molecular dissociations. (Author)

  11. Radiation damage on high polymer epoxies

    Energy Technology Data Exchange (ETDEWEB)

    Pak, H M [Royal Military Coll. of Canada, Kingston, ON (Canada)

    1994-12-31

    The effect of irradiation in a SLOWPOKE-2 reactor on the adhesive strength of epoxy resins was studied using the ASTM D897 standard testing procedure. Although the results were variable, indicating the doses were not well defined, nevertheless, there was evidence of strengthening associated with radiation-induced crosslinking. 2 figs., 1 tab.

  12. Radioactivity, shielding, radiation damage, and remote handling

    International Nuclear Information System (INIS)

    Wilson, M.T.

    1975-01-01

    Proton beams of a few hundred million electron volts of energy are capable of inducing hundreds of curies of activity per microampere of beam intensity into the materials they intercept. This adds a new dimension to the parameters that must be considered when designing and operating a high-intensity accelerator facility. Large investments must be made in shielding. The shielding itself may become activated and require special considerations as to its composition, location, and method of handling. Equipment must be designed to withstand large radiation dosages. Items such as vacuum seals, water tubing, and electrical insulation must be fabricated from radiation-resistant materials. Methods of maintaining and replacing equipment are required that limit the radiation dosages to workers.The high-intensity facilities of LAMPF, SIN, and TRIUMF and the high-energy facility of FERMILAB have each evolved a philosophy of radiation handling that matches their particular machine and physical plant layouts. Special tooling, commercial manipulator systems, remote viewing, and other techniques of the hot cell and fission reactor realms are finding application within accelerator facilities. (U.S.)

  13. Enhancement of radiation damage in germinating wheat seeds by hyperthermia

    International Nuclear Information System (INIS)

    Guo Fangqing; Gu Ruiqi

    1994-01-01

    Enhancement of X-ray induced radiation damage in germinating wheat seeds by heat treatment (44 degree C or 41 degree C, 20 min) has been investigated. The enhancement effect of heat treatment after irradiation was more significant than that of heat treatment before irradiation at dose range of 4.3-8.6 Gy. It was observed that germinating wheat seeds were very sensitive to heat treatment within 15 min after irradiation, which indicated that the repair of radiation damage was very active and rapid in a short period after irradiation. The repair of radiation damage in interval of fractionated irradiation was severely inhibited by heat treatment. The sensitivity of seeds to heat treatment corresponded with the levels of their repair activities. The more active the repairs of the seeds are, the more sensitive to heat treatment the seeds show. It was assumed that the enhancement of radiation damage by heat treatment in germinating wheat seeds was attributed to the inhibition of radiation damage repair by heat treatment, which is similar to the results of animal experiments

  14. Response of radiation monitoring labels to gamma rays and electrons

    DEFF Research Database (Denmark)

    Rahim, F. Abdel; Miller, Arne; McLaughlin, W.L.

    1985-01-01

    or location has been irradiated to high doses. Among labels available worldwide, a few are suitable for indicating absorbed dose regions of slightly less than 104 Gy (monitoring high dose ranges (i.e., sterilization dose levels of > 104 Gy or > 1 Mrad), and in some cases......, and differences in dose rate and radiation type (gamma rays and electron beams) were made on 15 kinds of labels. The results show that, for many types of indicators, diverse effects may give misleading conclusions unless countermeasures are taken. For example, some of the most commonly used labels, which contain...... permit somewhat more precise discrimination of dose levels, and may sometimes be useful for monitoring differences in local dose distributions or area monitoring of radiation damage probabilities around particle accelerators or large radionuclide sources....

  15. Study on DNA damages induced by UV radiation

    International Nuclear Information System (INIS)

    Doan Hong Van; Dinh Ba Tuan; Tran Tuan Anh; Nguyen Thuy Ngan; Ta Bich Thuan; Vo Thi Thuong Lan; Tran Minh Quynh; Nguyen Thi Thom

    2015-01-01

    DNA damages in Escherichia coli (E. coli) exposed to UV radiation have been investigated. After 30 min of exposure to UV radiation of 5 mJ/cm"2, the growth of E. coli in LB broth medium was about only 10% in compared with non-irradiated one. This results suggested that the UV radiation caused the damages for E. coli genome resulted in reduction in its growth and survival, and those lesions can be somewhat recovered. For both solutions of plasmid DNAs and E. coli cells containing plasmid DNA, this dose also caused the breakage on single and double strands of DNA, shifted the morphology of DNA plasmid from supercoiled to circular and linear forms. The formation of pyrimidine dimers upon UV radiation significantly reduced when the DNA was irradiated in the presence of Ganoderma lucidum extract. Thus, studies on UV-induced DNA damage at molecular level are very essential to determine the UV radiation doses corresponding to the DNA damages, especially for creation and selection of useful radiation-induced mutants, as well as elucidation the protective effects of the specific compounds against UV light. (author)

  16. REMOTE AREA RADIATION MONITORING (RARM) ALTERNATIVES ANALYSIS

    International Nuclear Information System (INIS)

    NELSON RL

    2008-01-01

    The Remote Area Radiation Monitoring (RARM) system will be used to provide real-time radiation monitoring information to the operations personnel during tank retrieval and transfer operations. The primary focus of the system is to detect potential anomalous (waste leaks) or transient radiological conditions. This system will provide mobile, real-time radiological monitoring, data logging, and status at pre-selected strategic points along the waste transfer route during tank retrieval operations. The system will provide early detection and response capabilities for the Retrieval and Closure Operations organization and Radiological Control personnel

  17. Radiation monitoring in high energy research facility

    International Nuclear Information System (INIS)

    Miyajima, Mitsuhiro

    1975-01-01

    In High Energy Physics Research Laboratory, construction of high energy proton accelerator is in progress. The accelerator is a cascaded machine comprising Cockcroft type (50 keV), linac (20 MeV), booster synchrotron (500 MeV), and synchrotron (8-12 GeV). Its proton beam intensity is 1x10 13 photons/pulse, and acceleration is carried out at the rate of every 2 minutes. The essential problems of radiation control in high energy accelerators are those of various radiations generated secondarily by proton beam and a number of induced radiations simultaneously originated with such secondary particles. In the Laboratory, controlled areas are divided into color-coded four regions, red, orange, yellow and green, based on each dose-rate. BF 3 counters covered with thick paraffin are used as neutron detectors, and side-window GM tubes, NaI (Tl) scintillators and ionization chambers as γ-detectors. In red region, however, ionization chambers are applied to induced radiation detection, and neutrons are not monitored. NIM standards are adopted for the circuits of all above monitors considering easy maintenance, economy and interchangeability. Notwithstanding the above described systems, these monitors are not sufficient to complete the measurement of whole radiations over wide energy region radiated from the accelerators. Hence separate radiation field measurement is required periodically. An example of the monitoring systems in National Accelerator Laboratory (U.S.) is referred at the last section. (Wakatsuki, Y.)

  18. Request from radiation damage evaluation in materials

    International Nuclear Information System (INIS)

    Fukuya, Koji; Kimura, Itsuro

    2003-01-01

    Radiation transport calculations in a PWR using cross-section data sets based on JENDL3.2 showed that the calculated neutron fluence agreed well with the dosimeter measurements and that the fast neutron flux and dpa rate differed within 10% from to those calculated using ENDF/B-IV and ENDF/B-VI based data sets. Calculations of helium generation in structural materials in the PWR using ENDF/B-VI showed that the dominant source of helium is the (n, α) reaction of 59 Ni and that the calculated helium content agreed with the measurements. For accurate estimation of radiation field from a material viewpoint, it is desirable to construct proper cross-section libraries, which have a proper energy group structure and contain sufficient elements including 59 Ni as an indispensable element. (author)

  19. Radiation damage to integrated injection logic cells

    International Nuclear Information System (INIS)

    Pease, R.L.; Galloway, K.F.; Stehlin, R.A.

    1975-01-01

    The effects of neutron and total dose gamma irradiations on the electrical characteristics of an integrated injection logic (l 2 L) cell and an l 2 L multiple inverter circuit were investigated. These units were designed and fabricated to obtain circuit development information and did not have radiation hardness as a goal. The following parameters of the test structures were measured as a function of total dose and neutron fluence: the dc common-base current gain of the lateral pnp transistor; the dc common-emitter current gain of the vertical npn transistor; the forward current-voltage characteristics of the injector-substrate junction, and the propagation delay versus power dissipation per gate for the multiple inverter circuit. The limitations of the present test structures in a radiation environment and possible hardening techniques are discussed

  20. Health and radiation: Surveillance and monitoring

    International Nuclear Information System (INIS)

    Reitan, J.B.; Langmark, F.

    1988-01-01

    Assuming a zero risk of low-dose radiation would allow society to save a lot of resources currently used in radiation protection. If this assumption should turn out to be wrong, however, the society would face a serious cancer problem within 20-40 years. Thus, the present resources allocated to radiation protection seem justified from an ethical and moral point of view. Such radiation protection should also include monitoring of naturally enhanced radiation and possibilities of contamination, and ecological changes from energy production, waste deposition and fertilizing. The weaker parts of establishing the dose/effect relationship are radiation biology and radiation medicine. Therefore, continued research in these disciplines should be encouraged

  1. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; van de Geijn, J.; Goffman, T. (ROB, DCT, NCI, NIH, Bethesda, Maryland 20892 (US))

    1991-05-01

    In the conventional linear--quadratic model of single-dose response, the {alpha} and {beta} terms reflect lethal damage created {ital during} the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD.

  2. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    International Nuclear Information System (INIS)

    Chen, J.; van de Geijn, J.; Goffman, T.

    1991-01-01

    In the conventional linear--quadratic model of single-dose response, the α and β terms reflect lethal damage created during the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with ''unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD

  3. APD Properties and Recovery from Radiation Damage

    CERN Document Server

    Baccaro, Stefania; Caruso, S; Cavallari, Francesca; Dafinei, Ioan; Diemoz, Marcella; Emeliantchik, Igor; Festinesi, Armando; Longo, Egidio; Montecchi, Marco; Organtini, Giovanni; Rosi, G

    1997-01-01

    Avalanche photodiodes will be used to detect scintillation light from PWO crystals in the CMS electromagnetic calorimeter. Properties of Hamamatsu APD are reported special attention has been devoted to the study of radiation hardness and room temperature annealing. We found a fast recovery with a time constant of 1.3 days a medium fast recovery with a lifetime of the order of 10 days and indication of a third component with very long time constant of the order of 300 days.

  4. BAKNET - Communication network for radiation monitoring devices

    International Nuclear Information System (INIS)

    Cohen, Y.; Wengrowicz, U.; Tirosh, D.; Barak, D.

    1997-01-01

    A system, based on a new concept of controlling and monitoring distributed radiation monitors, has been developed and approved at the NRCN. The system, named B AKNET Network , consists of a series of communication adapters connected to a main PC via an RS-485 communication network (see Fig. 1). The network's maximal length is 1200 meters and it enables connection of up to 128 adapters. The BAKNET adapters are designed to interface output signals of different types of stationary radiation monitors to a main PC. The BAKNET adapters' interface type includes: digital, analog, RS-232, and mixed output signals. This allows versatile interfacing of different stationary radiation monitors to the main computer. The connection to the main computer is via an RS-485 network, utilizing an identical communication protocol. The PC software, written in C ++ under MS-Windows, consists of two main programs. The first is the data collection program and the second is the Human Machine Interface (HMI). (authors)

  5. Radiachromic: a radiation monitoring system

    International Nuclear Information System (INIS)

    Humpherys, K.C.; Kantz, A.D.

    1977-01-01

    Various plastic film materials have been utilized to measure radiation fields. The radiachromic materials have been found to have advantages in reproducibility, stability, equivalent response to electrons and gamma ray fields, dose rate dependence and negligible variation for most environmental parameters. A simple photometer has been developed for read-out. The physical and chemical properties of the total system are described. A standard radiachromic has been selected for application to radiation processing. This material has a dose range of 5 x 10 4 to 3 x 10 7 rads, no dose rate effects to above 4 x 10 14 R/sec, an equivalent response to electrons and gamma rays, shelf life of greater than one year. Other forms are also applicable to radiation processing. (author)

  6. Radiation damage in flash memory cells

    International Nuclear Information System (INIS)

    Claeys, C.; Ohyama, H.; Simoen, E.; Nakabayashi, M.; Kobayashi, K.

    2002-01-01

    Results are presented of a study on the effects of total ionization dose and displacement damage, induced by high-energy electrons, protons and alphas, on the performance degradation of flash memory cells integrated in a microcomputer. A conventional stacked-gate n-channel flash memory cell using a 0.8 μm n-polysilicon gate technology is employed. Irradiations by 1-MeV electrons and 20-MeV protons and alpha particles were done at room temperature. The impact of the fluence on the input characteristics, threshold voltage shift and drain and gate leakage was investigated. The threshold voltage change for proton and alpha irradiations is about three orders of magnitude larger than that for electrons. The performance degradation is mainly caused by the total ionization dose (TID) damage in the tunnel oxide and in the interpoly dielectric layer and by the creation of interface traps at the Si-SiO 2 interface. The impact of the irradiation temperature on the device degradation was studied for electrons and gammas, pointing out that irradiation at room temperature is mostly the worst case. Finally, attention is given to the impact of isochronal and isothermal annealing on the recovery of the degradation introduced after room temperature proton and electron irradiation

  7. Damage of DNA by radiation and it's recovery, 3

    International Nuclear Information System (INIS)

    Narita, Noboru; Matsuura, Tomio; Sato, Hiroyuki.

    1974-01-01

    The damage and recovery of DNA was investigated by the incorporation of thymine derivatives (DHT, I trans, II trans, cis and glycol) into exponentially growing Tetrahymena cells. The strain employed was Tetrahymena pyriformis, Variety I, mating type IV. It is well known that these thymine derivatives are induced in vivo by radiation. The in vivo damage of DNA induced by radiation, and its recovery, were confirmed experimentally by means of gradient separation of sucrose density and by analytical ultra centrifugation (UVC). The recovery of DNA, its excision repair and its recombinational repair were compared with the recovery of Bacillus subtilis whose recovery kinetics were already known. 1) The damage of DNA was more sensitive to glycol than to II trans and cis. On the other hand, DHT is not sensitive for breaking DNA strand. 2) In its recovery damaged DNA was no more sensitive to glycol than to hhp as was true for Bacillus subtilis. (author)

  8. The dependence of radiation damage analysis on neutron dosimetry

    International Nuclear Information System (INIS)

    Goland, A.N.; Parkin, D.M.

    1977-01-01

    The characteristics of defect production in neutron spectra can be determined by utilizing neutron cross section data (e.g. ENDF/B), detailed neutron spectral data and radiation damage models. The combination of neutron cross section and spectral data is a fundamental starting point in applying damage models. Calculations using these data and damage models show that there are significant differences in the way defects are produced in various neutron spectra. Nonelastic events dominate the recoil energy distribution in high-energy neutron sources such as those based upon fusion and deuteron-breakup reactions. Therefore, high-energy neutron cross sections must be measured or calculated to supplement existing data files. Radiation damage models can then be used to further characterize the diverse neutron spectra

  9. THE ROLE OF RADIATION ACCIDENTS AND INDUSTRIAL APPLICATIONS OF IONIZING RADIATION SOURCES IN THE PROBLEM OF RADIATION DAMAGE

    OpenAIRE

    Кіхтенко, Ігор Миколайович

    2016-01-01

    Subject of research – the relevance of radiation damage at modern development of industry and medicine. In the world of radiation sources used in different fields of practice and their application in the future will increase, which greatly increases the likelihood of injury in a significant contingent of people.Research topic – the definition of the role of nuclear energy and the industrial use of ionizing radiation sources in the problem of radiation damage. The purpose of research – identif...

  10. Onboard monitoring of fatigue damage rates in the hull girder

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

    2011-01-01

    Most new advanced ships have extensive data collection systems to be used for continuous monitoring of engine and hull performance, for voyage performance evaluation etc. Such systems could be expanded to include also procedures for stress monitoring and for decision support, where the most...... critical wave-induced ship extreme responses and fatigue damage accumulation can be estimated for hypothetical changes in ship course and speed in the automatically estimated wave environment.The aim of this paper is to outline a calculation procedure for fatigue damage rate prediction in hull girders...... taking into account whipping stresses. It is conceptually shown how such a method, which integrates onboard estimation of sea states, can be used to deduce decision support with respect to the accumulated fatigue damage in the hull girder.The paper firstly presents a set of measured full-scale wave...

  11. Role of endothelium in radiation-induced normal tissue damages

    International Nuclear Information System (INIS)

    Milliat, F.

    2007-05-01

    More than half of cancers are treated with radiation therapy alone or in combination with surgery and/or chemotherapy. The goal of radiation therapy is to deliver enough ionising radiation to destroy cancer cells without exceeding the level that the surrounding healthy cells can tolerate. Unfortunately, radiation-induced normal tissue injury is still a dose limiting factor in the treatment of cancer with radiotherapy. The knowledge of normal tissue radiobiology is needed to determine molecular mechanisms involved in normal tissue pathogenic pathways in order to identify therapeutic targets and develop strategies to prevent and /or reduce side effects of radiation therapy. The endothelium is known to play a critical role in radiation-induced injury. Our work shows that endothelial cells promote vascular smooth muscle cell proliferation, migration and fibro-genic phenotype after irradiation. Moreover, we demonstrate for the first time the importance of PAI-1 in radiation-induced normal tissue damage suggesting that PAI-1 may represent a molecular target to limit injury following radiotherapy. We describe a new role for the TGF-b/Smad pathway in the pathogenesis of radiation-induced damages. TGF-b/Smad pathway is involved in the fibro-genic phenotype of VSMC induced by irradiated EC as well as in the radiation-induced PAI-1 expression in endothelial cells. (author)

  12. Radiation Damage Theory: Past, Present and Future

    International Nuclear Information System (INIS)

    Barashev, Aleksandr; Golubov, Stanislav I.

    2009-01-01

    Efforts of many scientists for more than a half of a century have resulted in substantial understanding of the response of various materials to irradiation. The theory has contributed significantly to this process but has not acquired a status allowing it to play a decisive role in creating radiation-resistant materials. Moreover, some theoretical predictions are in contradiction with observations, which indicates that something important has escaped attention. In the present paper, the current theoretical framework and experimental data are analyzed to elucidate the reasons for such a situation. A way of developing a predictive theory is proposed.

  13. Animal Models of Ionizing Radiation Damage

    Science.gov (United States)

    1992-01-01

    194. Stepanovic, S.R., and J.L. Nikolic, The Effect of X -irradiation on the Amount of Dopamine in Corpus Striatum of the Rat, Experientia, 35:111...Effect of X -irradiation on the Fragility of Rat Spleen Lysosomes, Radiat. Res., 20:741-750, 1963. 324. Rappaport, D.A., Influence of Total-body X -rays...NUMER C DOMB No. 0704-0188 Pubk€ "mt burden for Vft collectio al 0.0oni is san i jo avwa I how nemeai m n k x W o rqvWin srucilim seard" af da sources

  14. Radiation damage effects on calorimeter compensation

    International Nuclear Information System (INIS)

    Gabriel, T.A.; Handler, T.

    1990-01-01

    An important consideration in the design of a detector that is to be used at the Superconducting Super Collider (SSC) is the response of the calorimeter to electromagnetic and hadronic particles and the equality of those responses for different types of particles at equal incident energies, i.e. compensation. However, as the simulations that are reported show, the compensation characteristics of a calorimeter can be seriously compromised over a relatively short period of time due to the large radiation levels that are expected in the SSC environment. 6 refs., 3 figs

  15. ANL/WSU radiation damage studies

    International Nuclear Information System (INIS)

    Jankowski, D.; Lopiano, D.; Proudfoot, J.; Underwood, D.; Miles, L.; Neidiger, J.; Tripard, G.

    1993-01-01

    We report preliminary results for the radiation hardness of (polystryrene) plastic scintillator stacks using a spectrum of energy hardened neutrons from a MARK-III TRIGA reactor. The total dose ranged from 100 KRad to 3MRad. The corresponding fluence was 3.8 x 10 13 to 3.8 x 10 14 (n/cm/cm) with the gamma contribution on the order 2--3% (of fluence). The measurements used Li-6, Li-7 Thermo-luminescence dosimeters. Radiochromic/GaF- Chromic film, and activated foils simultaneously allowing an inter-comparison of these various methods of dosimetry

  16. Post-accident radiation monitors

    International Nuclear Information System (INIS)

    Laughlin, G.J.; Kathren, R.L.

    1982-01-01

    Under contract to the Nuclear Safety Analysis Center of the Electric Power Research Institute, technical information and specifications were obtained for commercially available radiological monitoring instrumentation designed for use as post-accident monitors. The information was collated and published in the NSAC Handbook of Postaccident Instrumentation (Kathren and Laughlin 1981), and included such data as range, accuracy, precision, sensitivity, and energy dependence of the detector, environmental and seismic limitations of the equipment, the testing program performed to evaluate the equipment, a list of references where the instrumentation is currently installed, and a list of features and accessories available with the monitoring systems. The information presented in this section reveals that, even though a number of vendors claim to be able to meet the guidance of Regulatory Guide 1.97 (USNRC 1980), few have actually conducted tests to verify that their equipment does indeed satisfy the guidance of this Regulatory Guide, and that some of the guidance may in fact be unrealistic

  17. Raman study of radiation-damaged zircon under hydrostatic compression

    Science.gov (United States)

    Nasdala, Lutz; Miletich, Ronald; Ruschel, Katja; Váczi, Tamás

    2008-12-01

    Pressure-induced changes of Raman band parameters of four natural, gem-quality zircon samples with different degrees of self-irradiation damage, and synthetic ZrSiO4 without radiation damage, have been studied under hydrostatic compression in a diamond anvil cell up to ~10 GPa. Radiation-damaged zircon shows similar up-shifts of internal SiO4 stretching modes at elevated pressures as non-damaged ZrSiO4. Only minor changes of band-widths were observed in all cases. This makes it possible to estimate the degree of radiation damage from the width of the ν3(SiO4) band of zircon inclusions in situ, almost independent from potential “fossilized pressures” or compressive strain acting on the inclusions. An application is the non-destructive analysis of gemstones such as corundum or spinel: broadened Raman bands are a reliable indicator of self-irradiation damage in zircon inclusions, whose presence allows one to exclude artificial color enhancement by high-temperature treatment of the specimen.

  18. Radiation damage of pixelated photon detector by neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Isamu [KEK, 1-1 Oho Tsukuba 305-0801 (Japan)], E-mail: isamu.nakamura@kek.jp

    2009-10-21

    Radiation Damage of Pixelated Photon Detector by neutron irradiation is reported. MPPC, one of PPD or Geiger-mode APD, developed by Hamamatsu Photonics, is planned to be used in many high energy physics experiments. In such experiments radiation damage is a serious issue. A series of neutron irradiation tests is performed at the Reactor YAYOI of the University of Tokyo. MPPCs were irradiated at the reactor up to 10{sup 12}neutron/cm{sup 2}. In this paper, the effect of neutron irradiation on the basic characteristics of PPD including gain, noise rate, photon detection efficiency is presented.

  19. Multiscale approach to the physics of radiation damage with ions

    Energy Technology Data Exchange (ETDEWEB)

    Surdutovich, Eugene [Physics Department, Oakland University, 2200 N. Squirrel Rd., Rochester MI 48309 (United States); Solov' yov, Andrey V. [Frankfurt Institute for Advanced Studies, Goethe University, Ruth-Moufang-Str. 1, Frankfurt am Main 60438 (Germany)

    2013-04-19

    We review a multiscale approach to the physics of ion-beam cancer therapy, an approach suggested in order to understand the interplay of a large number of phenomena involved in radiation damage scenario occurring on a range of temporal, spatial, and energy scales. We briefly overview its history and present the current stage of its development. The differences of the multiscale approach from other methods of understanding and assessment of radiation damage are discussed as well as its relationship to other branches of physics, chemistry and biology.

  20. A novel theory of radiation damage at high doses

    International Nuclear Information System (INIS)

    Seeger, A.; Stuttgart Univ.

    1989-01-01

    Deviations of radiation damage (in the case of metals usually monitored by the residual electrical resistivity) from proportionality with the irradiation dose have so far been analysed almost exclusively in terms of extensions of models originally developed for small doses. The present theory considers the opposite limit i.e. the quasi-saturated state. It is argued that at high doses the Lueck-Sizmann effect may result in a self-organization of clusters of vacancies and self-interstitials, forming a heterogeneous froth. Possible structures of this froth and its effect on the electrical resistivity of metals are discussed. The model is shown to account for the dependence of the ''saturation resistivity'' on the nature of the irradiation as well as for several other hitherto poorly explained observations. Among them are the electrical-resistivity variation induced by high-dose irradiation with heavy ions, the amorphization of certain alloys by high-dose electron irradiation, and the occurrence of ordered arrays of stacking-fault tetrahedra after in-situ irradiations in high-voltage electron microscopes. (author)

  1. Radiation damage studies related to nuclear waste forms

    International Nuclear Information System (INIS)

    Gray, W.J.; Wald, J.W.; Turcotte, R.P.

    1981-12-01

    Much of the previously reported work on alpha radiation effects on crystalline phases of importance to nuclear waste forms has been derived from radiation effects studies of composite waste forms. In the present work, two single-phase crystalline materials, Gd 2 Ti 2 O 7 (pyrochlore) and CaZrTi 2 O 7 (zirconolite), of relative importance to current waste forms were studied independently by doping with 244 Cm at the 3 wt % level. Changes in the crystalline structure measured by x-ray diffraction as a function of dose show that damage ingrowth follows an expected exponential relationship of the form ΔV/V 0 = A[1-exp(-BD)]. In both cases, the materials became x-ray amorphous before the estimated saturation value was reached. The predicted magnitudes of the unit cell volume changes at saturation are 5.4% and 3.5%, respectively, for Gd 2 Ti 2 O 7 and CaZrTi 2 O 7 . The later material exhibited anisotropic behavior in which the expansion of the monoclinic cell in the c 0 direction was over five times that of the a 0 direction. The effects of transmutations on the properties of high-level waste solids have not been studied until now because of the long half-lives of the important fission products. This problem was circumvented in the present study by preparing materials containing natural cesium and then irradiating them with neutrons to produce 134 Cs, which has only a 2y half-life. The properties monitored at about one year intervals following irradiation have been density, leach rate and microstructure. A small amount of x-ray diffraction work has also been done. Small changes in density and leach rate have been observed for some of the materials, but they were not large enough to be of any consequence for the final disposal of high level wastes

  2. Radiation damage in BaF2 crystals

    International Nuclear Information System (INIS)

    Woody, C.L.; Kierstead, J.A.; Levy, P.W.; Stoll, S.

    1991-01-01

    The effects of radiation damage and recovery have been studied in BaF 2 crystals exposed to 60 Co radiation. The change in optical transmission and scintillation light output have been measured as a function of dose up to 4.7 x 10 6 rad. Although some crystals exhibit a small change in transmission, a greater change in scintillation light output is observed. Several 25 cm long crystals whichhave been irradiated show large changes in both transmission and light output. Recovery from radiation damage has been studied as a function of time and exposure to UV light. A long lived radiation induced phosphorescence has been observed in all irradiated samples which is distinct from the standard fast and slow scintillation emissions. The emission spectrum of the phosphorescence has been measured and shown a peakat ∼330 nm, near the region of the slow scintillation component. Results are given on the dependence of the decay time of the phosphorescence with dose

  3. Genomic damage in children accidentally exposed to ionizing radiation

    DEFF Research Database (Denmark)

    Fucic, A; Brunborg, G; Lasan, R

    2007-01-01

    During the last decade, our knowledge of the mechanisms by which children respond to exposures to physical and chemical agents present in the environment, has significantly increased. Results of recent projects and programmes focused on children's health underline a specific vulnerability of chil...... and efficient preventive measures, by means of a better knowledge of the early and delayed health effects in children resulting from radiation exposure....... of children to environmental genotoxicants. Environmental research on children predominantly investigates the health effects of air pollution while effects from radiation exposure deserve more attention. The main sources of knowledge on genome damage of children exposed to radiation are studies performed...... after the Chernobyl nuclear plant accident in 1986. The present review presents and discusses data collected from papers analyzing genome damage in children environmentally exposed to ionizing radiation. Overall, the evidence from the studies conducted following the Chernobyl accident, nuclear tests...

  4. Alleviation of acute radiation damages by post-irradiation treatments

    International Nuclear Information System (INIS)

    Kurishita, A.; Ono, T.

    1992-01-01

    Radiation induced hematopoietic and gastro-intestinal damages in mice were tried to alleviate experimentally by post-treatment. Combined treatment of OK-432 and aztreonam clearly prevented the radiation induced sepsis and elevated the survival rate in mice; the survival was 80% in the OK-432 plus aztreonam group while it was 55% in the group treated with OK-432 alone and 0% with saline. Irsogladine maleate, an anti-ulcer drug, increased the survival rate of jejunal crypt stem cells with a clear dose-related trend. The D 0 for irsogladine maleate was 2.8 Gy although it was 2.3 Gy for saline, These findings suggest that some conventional drugs are effective for radiation induced hematopoietic and gastro-intestinal damages and the possibility that they can be applied for people exposed to radiation accidentally. (author)

  5. Radiation induced DNA damage and repair in mutagenesis

    International Nuclear Information System (INIS)

    Strniste, G.F.; Chen, D.J.; Okinaka, R.T.

    1987-01-01

    The central theme in cellular radiobiological research has been the mechanisms of radiation action and the physiological response of cells to this action. Considerable effort has been directed toward the characterization of radiation-induced DNA damage and the correlation of this damage to cellular genetic change that is expressed as mutation or initiating events leading to cellular transformation and ultimately carcinogenesis. In addition, there has been a significant advancement in their understanding of the role of DNA repair in the process of mutation leading to genetic change in cells. There is extensive literature concerning studies that address radiation action in both procaryotic and eucaryotic systems. This brief report will make no attempt to summarize this voluminous data but will focus on recent results from their laboratory of experiments in which they have examined, at both the cellular and molecular levels, the process of ionizing radiation-induced mutagenesis in cultured human cells

  6. Radiation damage in nonmetallic solids under dense electronic excitation

    International Nuclear Information System (INIS)

    Itoh, Noriaki; Tanimura, Katsumi; Nakai, Yasuo

    1992-01-01

    Basic processes of radiation damage of insulators by dense electronic excitation are reviewed. First it is pointed out that electronic excitation of nonmetallic solids produces the self-trapped excitons and defect-related metastable states having relatively long lifetimes, and that the excitation of these metastable states, produces stable defects. The effects of irradiation with heavy ions, including track registration, are surveyed on the basis of the microscopic studies. It is pointed out also that the excitation of the metastable states plays a role in laser-induced damage at relatively low fluences, while the laser damage has been reported to be governed by heating of free electrons produced by multiphoton excitation. Difference in the contributions of the excitation of metastable defects to laser-induced damage of surfaces, or laser ablation, and laser-induced bulk damage is stressed. (orig.)

  7. Radiation monitoring at Sizewell B PWR

    International Nuclear Information System (INIS)

    Hills, O.C.

    1992-01-01

    Radiation monitoring in Sizewell-B Power Station most significantly differs from that in existing UK Power Stations in two respects: firstly in the large number of on-line radiation monitors and secondly in the way that the monitors are linked into a fully-integrated, centralised data acquisition and display system, which can be accessed and viewed by the operators. An overview is given of how full process data is transmitted along data links between the Auxiliary Shut-Down Room, Technical Support Centre and Main Control Room, enabling Health Physics and other staff to access information from any radiation monitor. The permanently installed monitors together with the safety category, type and location are listed. As part of the Sizewell-B Process Plant control and instrumentation contract, NEI is to supply the Health Physics Instrumentation (HPI) and Process and Effluent Activity Monitoring System (PEAMS) (excluding the Primary Protection System) plus the Nuclear Sampling System (NSS). This paper concentrates on the HPI, and parts of the PEAMS and NSS for which NEI have the responsibility for system design, detail design, manufacture, site installation and commissioning. Section 2 briefly describes the sources of radiation at Sizewell-B; Sections 3, 4 and 5 describe the PEAMS, HPI and NSS respectively. Section 6 details the design of two of the Sizewell-B PEAMS subsystems. (Author)

  8. Ion irradiation and biomolecular radiation damage II. Indirect effect

    OpenAIRE

    Wang, Wei; Yu, Zengliang; Su, Wenhui

    2010-01-01

    It has been reported that damage of genome in a living cell by ionizing radiation is about one-third direct and two-thirds indirect. The former which has been introduced in our last paper, concerns direct energy deposition and ionizing reactions in the biomolecules; the latter results from radiation induced reactive species (mainly radicals) in the medium (mainly water) surrounding the biomolecules. In this review, a short description of ion implantation induced radical formation in water is ...

  9. Modification of radiation damage by naturally occurring substances

    International Nuclear Information System (INIS)

    Prasad, K.N.

    1984-01-01

    The major objectives of studying the modification of radiation sensitivity have been (1) to identify a compound that will produce a differential protection or sensitization of the effect of irradiation on normal and tumor tissue, and (2) to understand more about the mechanisms of radiation damage. In spite of massive research on this particular problem since World War II, the first objective remains elusive. During this period, numerous radioprotective and radiosensitizing agents have been identified. These agents have served as important biologic tools for increasing our understanding of radiation injuries. Most of these substances are synthetic compounds and are very toxic to humans. In addition, very few of the compounds provide differential modifications of the effect of radiation on tumor and normal cells. This chapter presents objectives for identifying naturally occurring substances that modify the effect of x-radiation on mammalian cells and discusses the role of physiologic substances in modifying radiation injuries on mammalian normal and tumor cells

  10. Radiation damage to DNA: The importance of track structure

    International Nuclear Information System (INIS)

    Hill, M.A.

    1999-01-01

    A wide variety of biological effects are induced by ionizing radiation, from cell death to mutations and carcinogenesis. The biological effectiveness is found to vary not only with the absorbed dose but also with the type of radiation and its energy, i.e., with the nature of radiation tracks. An overview is presented of some of the biological experiments using different qualities of radiation, which when compared with Monte Carlo track structure studies, have highlighted the importance of the localized spatial properties of stochastic energy deposition on the nanometer scale at or near DNA. The track structure leads to clustering of damage which may include DNA breaks, base damage etc., the complexity of the cluster and therefore its biological repairability varying with radiation type. The ability of individual tracks to produce clustered damage, and the subsequent biological response are important in the assessment of the risk associated with low-level human exposure. Recent experiments have also shown that biological response to radiation is not always restricted to the 'hit' cell but can sometimes be induced in 'un-hit' cells near by

  11. Radiation damage in carbon-carbon composites

    International Nuclear Information System (INIS)

    Burchell, T.D.; Eartherly, W.P.; Nelson, G.E.

    1992-01-01

    Graphite and carbon-carbon composite materials are widely used in plasma facing applications in current Tokamak devices such as TFTR and DIIID in the USA, JET, Tore Supra and TEXTOR in Europe, and JT-60U in Japan. Carbon-carbon composites are attractive choices for Tokamak limiters and diverters because of their low atomic number, high thermal shock resistance, high melting point, and high thermal conductivity. Next generation machines such as the International Thermonuclear Experimental Reactor (ITER) will utilize carbon-carbon composites in their first wall and diverter. ITER will be an ignition machine and thus will produce substantial neutron fluences from the D-T fusion reaction. The resultant high energy neutrons will cause carbon atom displacements in the plasma facing materials which will markedly affect their structure and physical properties. The effect of neutron damage on graphite has been studied for over forty years. Recently the effects of neutron irradiation on the fusion relevant graphite GraphNOL N3M was reviewed. In contrast to graphite, relatively little work has been performed to elucidate the effects of neutron irradiation on carbon-carbon composites. The results of our previous irradiation experiments have been published elsewhere. Here the irradiation induced dimensional changes in 1D, 2D, and 3D carbon-carbon composites are reported for fluences up to 4.7 dpa at an irradiation temperature of 600 degree C

  12. Occupational radiation exposure monitoring among radiation workers in Nepal

    International Nuclear Information System (INIS)

    Bhatt, Chhavi Raj; Shrestha, Shanta Lall; Khanal, Tara; Ween, Borgny

    2008-01-01

    Nepal was accepted as a member of the IAEA in 2007. Nepal is one of the world's least developed countries and is defined in Health Level IV. The population counted 26.4 millions in 2007. The health care sector increases with new hospitals and clinics, however, Nepal has no radiation protection authority or radiation protection regulation in the country until now. The radiation producing equipment in the health sector includes conventional X-ray and dental X-ray equipment, fluoroscopes, mammography, CT, catheterization laboratory equipment, nuclear medicine facilities, a few linear accelerators, Co 60 teletherapy and High Dose Rate brachytherapy sources. The situation regarding dosimetry service for radiation workers is unclear. A survey has been carried out to give an overview of the situation. The data collection of the survey was performed by phone call interviews with responsible staff at the different hospitals and clinics. Data about different occupationally exposed staff, use of personal radiation monitoring and type of dosimetry system were collected. In addition, it was asked if dosimetry reports were compiled in files or databases for further follow-up of staff, if needed. The survey shows that less of 25% of the procedures performed on the surveyed hospitals and clinics are performed by staff with personnel radiation monitoring. Radiation monitoring service for exposed staff is not compulsory or standardized, since there is no radiation protection authority. Nepal has taken a step forward regarding radiation protection, with the IAEA membership, although there are still major problems that have to be solved. An evaluation of the existing practice of staff dosimetry can be the first helpful step for further work in building a national radiation protection authority. (author)

  13. Radiation-induced normal tissue damage: implications for radiotherapy

    International Nuclear Information System (INIS)

    Prasanna, Pataje G.

    2014-01-01

    Radiotherapy is an important treatment modality for many malignancies, either alone or as a part of combined modality treatment. However, despite technological advances in physical treatment delivery, patients suffer adverse effects from radiation therapy due to normal tissue damage. These side effects may be acute, occurring during or within weeks after therapy, or intermediate to late, occurring months to years after therapy. Minimizing normal tissue damage from radiotherapy will allow enhancement of tumor killing and improve tumor control and patients quality of life. Understanding mechanisms through which radiation toxicity develops in normal tissue will facilitate the development of next generation radiation effect modulators. Translation of these agents to the clinic will also require an understanding of the impact of these protectors and mitigators on tumor radiation response. In addition, normal tissues vary in radiobiologically important ways, including organ sensitivity to radiation, cellular turnover rate, and differences in mechanisms of injury manifestation and damage response. Therefore, successful development of radiation modulators may require multiple approaches to address organ/site-specific needs. These may include treatments that modify cellular damage and death processes, inflammation, alteration of normal flora, wound healing, tissue regeneration and others, specifically to counter cancer site-specific adverse effects. Further, an understanding of mechanisms of normal tissue damage will allow development of predictive biomarkers; however harmonization of such assays is critical. This is a necessary step towards patient-specific treatment customization. Examples of important adverse effects of radiotherapy either alone or in conjunction with chemotherapy, and important limitations in the current approaches of using radioprotectors for improving therapeutic outcome will be highlighted. (author)

  14. Reference calorimeter for radiation monitoring

    International Nuclear Information System (INIS)

    Zajic, V.; Vanek, V.

    1978-01-01

    The miniature sensor for gamma dose rate monitoring in nuclear reactors essentially consists of an absorption body symmetrically placed in a gas-tight sealed case and suspended on a metal pull-rod attached to the jacketed thermocouple bushing. The inner thermocouple is inserted into the centre of the absorption body through a slant port while the outer thermocouple is let out of the case at a point above the absorption body. (J.P.)

  15. Radiation monitoring in interventional cardiology: a requirement

    Science.gov (United States)

    Rivera, T.; Uruchurtu, E. S.

    2017-01-01

    The increasing of procedures using fluoroscopy in interventional cardiology procedures may increase medical and patients to levels of radiation that manifest in unintended outcomes. Such outcomes may include skin injury and cancer. The cardiologists and other staff members in interventional cardiology are usually working close to the area under examination and they receive the dose primarily from scattered radiation from the patient. Mexico does not have a formal policy for monitoring and recording the radiation dose delivered in hemodynamic establishments. Deterministic risk management can be improved by monitoring the radiation delivered from X-ray devices. The objective of this paper is to provide cardiologist, techniques, nurses, and all medical staff an information on DR levels, about X-ray risks and a simple a reliable method to control cumulative dose.

  16. Workplace monitoring for radiation and contamination

    International Nuclear Information System (INIS)

    1995-01-01

    Ionizing radiations cannot be seen, felt or sensed by the human body in any way but excessive exposure to them may have adverse health effects. In order to avoid excessive exposure, appropriate and efficient radiation measuring instruments are needed. This Module explains the basic terminology associated with such measuring instruments and describes the principal types, their construction and typical applications in the workplace. It is important to ensure not only that monitoring is carried out where there is a potential radiation exposure but also that the monitoring instrument is appropriate to the task and that the user places correct interpretations on the results obtained. The Manual will be of most benefit if it forms part of more comprehensive training or is supplemented by the advice of a qualified expert in radiation protection. Some of the instrument tests and calibrations described in this Module require the services of a qualified expert

  17. Wide range radiation monitoring apparatus

    International Nuclear Information System (INIS)

    Goldstein, N.P.

    1983-01-01

    There is described a simple and rugged detector capable of measuring radiation fields over the range of 0.02 R/hr up to 10/8 R/hr or higher. The device consists of an emitter element of high atomic number material which is connected to the center conductor of a signal cable. This emitter element is positioned in a spaced-apart relationship between collector element of a low atomic number material with a gap region between the emitter element and the adjacent collector elements

  18. LHCb: Radiation Damage in the LHCb VELO

    CERN Multimedia

    Rodriguez Perez, P

    2012-01-01

    LHCb is a dedicated experiment to study new physics in the decays of beauty and charm hadrons at the Large Hadron Collider (LHC) at CERN. The beauty and charm hadrons are identified through their flight distance in the Vertex Locator (VELO), and hence the detector is critical for both the trigger and offline physics analyses. The 88 VELO sensors are all n-on-n type but one, which is made from n-on-p silicon, and is the only n-on-p module silicon sensor operated at the LHC. The sensors have an inner radius of only 7 mm from the LHC beam and an outer radius of 42 mm, consequently the sensors receive a large and non-uniform radiation dose. The LHCb is planned to record an integrated luminosity up to 5 $fb^{-1}$ with collision energies between 7 and 14 TeV before 2018. The leakage current in the sensors has increased significantly following the delivered luminosity, and decreased during shutdown periods due to annealing. The effective depletion voltage of the sensors is measured from the charge collection effi...

  19. Automated TLD system for gamma radiation monitoring

    International Nuclear Information System (INIS)

    Nyberg, P.C.; Ott, J.D.; Edmonds, C.M.; Hopper, J.L.

    1979-01-01

    A gamma radiation monitoring system utilizing a commercially available TLD reader and unique microcomputer control has been built to assess the external radiation exposure to the resident population near a nuclear weapons testing facility. Maximum use of the microcomputer was made to increase the efficiency of data acquisition, transmission, and preparation, and to reduce operational costs. The system was tested for conformance with an applicable national standard for TLD's used in environmental measurements

  20. The RM-5000 system for radiation monitoring

    International Nuclear Information System (INIS)

    1997-01-01

    Eight models of radiation monitors can be assembled from independent modules for the agricultural firms, customs house, boundary transitions, for the control of transport and passenger flows and for prevention of the non-authorized moving of radioactive and fissionable materials. Two modules are a basis of the system - gamma radiation detector on the basis of plastic scintillator and neutrons detector on the basis of the proportional 3 He counters

  1. UV and ionizing radiations induced DNA damage, differences and similarities

    Science.gov (United States)

    Ravanat, Jean-Luc; Douki, Thierry

    2016-11-01

    Both UV and ionizing radiations damage DNA. Two main mechanisms, so-called direct and indirect pathways, are involved in the degradation of DNA induced by ionizing radiations. The direct effect of radiation corresponds to direct ionization of DNA (one electron ejection) whereas indirect effects are produced by reactive oxygen species generated through water radiolysis, including the highly reactive hydroxyl radicals, which damage DNA. UV (and visible) light damages DNA by again two distinct mechanisms. UVC and to a lesser extend UVB photons are directly absorbed by DNA bases, generating their excited states that are at the origin of the formation of pyrimidine dimers. UVA (and visible) light by interaction with endogenous or exogenous photosensitizers induce the formation of DNA damage through photosensitization reactions. The excited photosensitizer is able to induce either a one-electron oxidation of DNA (type I) or to produce singlet oxygen (type II) that reacts with DNA. In addition, through an energy transfer from the excited photosensitizer to DNA bases (sometime called type III mechanism) formation of pyrimidine dimers could be produced. Interestingly it has been shown recently that pyrimidine dimers are also produced by direct absorption of UVA light by DNA, even if absorption of DNA bases at these wavelengths is very low. It should be stressed that some excited photosensitizers (such as psoralens) could add directly to DNA bases to generate adducts. The review will described the differences and similarities in terms of damage formation (structure and mechanisms) between these two physical genotoxic agents.

  2. Potential radiation damage: Storage tanks for liquid radioactive waste

    International Nuclear Information System (INIS)

    Caskey, G.R. Jr.

    1992-01-01

    High level waste at SRS is stored in carbon steel tanks constructed during the period 1951 to 1981. This waste contains radionuclides that decay by alpha, beta, or gamma emission or are spontaneous neutronsources. Thus, a low intensity radiation field is generated that is capable of causing displacement damage to the carbon steel. The potential for degradation of mechanical properties was evaluated by comparing the estimated displacement damage with published data relating changes in Charpy V-notch (CVN) impact energy to neutron exposure. Experimental radiation data was available for three of the four grades of carbonsteel from which the tanks were constructed and is applicable to all four steels. Estimates of displacement damage arising from gamma and neutron radiation have been made based on the radionuclide contents for high level waste that are cited in the Safety Analysis Report (SAR) for the Liquid Waste Handling Facilities in the 200-Area. Alpha and beta emissions do not penetrate carbon steel to a sufficient depth to affect the bulk properties of the tank walls but may aggravate corrosion processes. The damage estimates take into account the source of the waste (F- or H-Area), the several types of tank service, and assume wateras an attenuating medium. Estimates of displacement damage are conservative because they are based on the highest levels of radionuclide contents reported in the SAR and continuous replenishment of the radionuclides

  3. Modernization of WWER-1000 radiation monitoring systems

    International Nuclear Information System (INIS)

    Smith, T.

    1995-01-01

    A modernization scheme of the radiation monitoring system for WWER-1000 is proposed. It has a purpose to comply with international standards and to reduce operational and maintenance cost by deleting obsolete components and reducing the number of detector channels. Detailed layouts of I/C system architecture, digital radiation monitoring system (DRAMS) architecture and LRP block diagram are presented. If planned and implemented properly, this program can provide cost savings by reducing time required to access and display data and maintenance cost by deleting obsolete parts and decreasing the number of detector channels. 3 figs

  4. Modernization of WWER-1000 radiation monitoring systems

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T [General Atomics, San Diego, CA (United States)

    1996-12-31

    A modernization scheme of the radiation monitoring system for WWER-1000 is proposed. It has a purpose to comply with international standards and to reduce operational and maintenance cost by deleting obsolete components and reducing the number of detector channels. Detailed layouts of I/C system architecture, digital radiation monitoring system (DRAMS) architecture and LRP block diagram are presented. If planned and implemented properly, this program can provide cost savings by reducing time required to access and display data and maintenance cost by deleting obsolete parts and decreasing the number of detector channels. 3 figs.

  5. Investigations into radiation damages of reactor materials by computer simulation

    International Nuclear Information System (INIS)

    Bronnikov, V.A.

    2004-01-01

    Data on the state of works in European countries in the field of computerized simulation of radiation damages of reactor materials under the context of the international projects ITEM (European Database for Multiscale Modelling) and SIRENA (Simulation of Radiation Effects in Zr-Nb alloys) - computerized simulation of stress corrosion when contact of Zr-Nb alloys with iodine are presented. Computer codes for the simulation of radiation effects in reactor materials were developed. European Database for Multiscale Modelling (EDAM) was organized using the results of the investigations provided in the ITEM project [ru

  6. Nuclear data for radiation damage assessment and related safety aspects

    International Nuclear Information System (INIS)

    Kocherov, N.P.

    1989-12-01

    The IAEA Advisory Group Meeting on Nuclear Data for Radiation Damage Assessment and Related Safety Aspects was held at the IAEA Headquarters in Vienna, 19-22 September 1989. This report contains the conclusions and recommendations of this meeting. The papers which the participants prepared for and presented at the meeting will be published as an IAEA Technical Document. (author)

  7. Effect of Rosiglitazone on Radiation Damage in Bone Marrow Hemopoiesis

    International Nuclear Information System (INIS)

    Benko', Klara; Pintye, Eva; Szabo, Boglarka; Geresi, Krisztina; Megyeri, Attila; Benko, Ilona

    2008-01-01

    To study radiobiological effects and drugs, which can modify radiation injury, has an importance if we would like to avoid harmful effects of radiation due to emergency situations or treat patients with malignant diseases by radiotherapy. During the long treatment schedules patients may be treated by not only anticancer but many other drugs because of accompanying diseases. These drugs may also modify radiobiological effects. Rosiglitazone pre-treatment proved to be myeloprotective and accelerated recovery of 5-fluorouracil-damaged bone marrow in our previous experiments. Our new studies are designed to evaluate whether rosiglitazone has similar beneficial effects in radiation-damaged hemopoiesis. Bone marrow damage was precipitated by total body irradiation (TBI) using single increasing doses (2-10 Gy) of γ--irradiation in groups of mice. Lethality was well correlated with damage in hemopoiesis measured by cellularity of bone marrow (LD 50 values were 4.8 and 5.3 gray respectively). Rosiglitazone, an insulin-sensitizing drug, had no significant effect on bone marrow cellularity. Insulin resistance associated with obesity or diabetes mellitus type 2 is intensively growing among cancer patients requiring some kind of radiotherapy. Therefore it is important to know whether drugs used for their therapy can modify radiation effects.

  8. Effect of Rosiglitazone on Radiation Damage in Bone Marrow Hemopoiesis

    Science.gov (United States)

    Benkő, Klára; Pintye, Éva; Szabó, Boglárka; Géresi, Krisztina; Megyeri, Attila; Benkő, Ilona

    2008-12-01

    To study radiobiological effects and drugs, which can modify radiation injury, has an importance if we would like to avoid harmful effects of radiation due to emergency situations or treat patients with malignant diseases by radiotherapy. During the long treatment schedules patients may be treated by not only anticancer but many other drugs because of accompanying diseases. These drugs may also modify radiobiological effects. Rosiglitazone pre-treatment proved to be myeloprotective and accelerated recovery of 5-fluorouracil-damaged bone marrow in our previous experiments. Our new studies are designed to evaluate whether rosiglitazone has similar beneficial effects in radiation-damaged hemopoiesis. Bone marrow damage was precipitated by total body irradiation (TBI) using single increasing doses (2-10 Gy) of γ—irradiation in groups of mice. Lethality was well correlated with damage in hemopoiesis measured by cellularity of bone marrow (LD50 values were 4.8 and 5.3 gray respectively). Rosiglitazone, an insulin-sensitizing drug, had no significant effect on bone marrow cellularity. Insulin resistance associated with obesity or diabetes mellitus type 2 is intensively growing among cancer patients requiring some kind of radiotherapy. Therefore it is important to know whether drugs used for their therapy can modify radiation effects.

  9. Experimental data available for radiation damage modelling in reactor materials

    International Nuclear Information System (INIS)

    Wollenberger, H.

    Radiation damage modelling requires rate constants for production, annihilation and trapping of defects. The literature is reviewed with respect to experimental determination of such constants. Useful quantitative information exists only for Cu and Al. Special emphasis is given to the temperature dependence of the rate constants

  10. Evaluation of gamma radiation induced genetic damage in the fish Cyprinus carpio using comet assay

    International Nuclear Information System (INIS)

    Praveen Kumar, M.K.; Shyama, S.K.; Bhagat, S.S.; Chaubey, R.C.

    2013-01-01

    Radionuclides released from various sources including the industries, as well as, accidental release during a nuclear disaster can contaminate inland water bodies. Suitable bio-monitoring methods/biomarkers are the need of the day to assess the impact of high/low levels of radiation exposure in aquatic environment. Fishes are very important as a group of ecologically and commercially important non-human biota and are often used as a bioindicators of aquatic pollution. Present work was carried out to assess the genotoxic effect of gamma radiation on fresh water fish Cyprinus carpio (common carp) in vivo using comet assay. Fishes were irradiated with 2, 4, 6, 8 and 10 Gy of gamma rays using a teletherapy machine and comet assay was performed on nucleated erythrocytes after 24, 48 and 72 h of irradiation . A significant increase in % tail DNA was observed at all the doses of gamma radiation as compared to controls indicating radiation induced DNA damage in a dose-dependent manner. Maximum % tail DNA was observed at 24 h which gradually declined till 72 h, in a time-dependent manner. This decrease in damage may indicate repair of the damaged DNA and or loss of heavily damaged cells, over a period of time. The study reveals that the comet assay may be used as a sensitive and rapid method to detect genotoxicity of gamma radiation and other environmental pollutants in sentinel species. (author)

  11. Ion bombardment simulation: a review related to fusion radiation damage

    International Nuclear Information System (INIS)

    Brimhall, J.L.

    1975-01-01

    Prime emphasis is given to reviewing the ion bombardment data on the refractory metals molybdenum, niobium and vanadium which have been proposed for use in advanced fusion devices. The temperature and dose dependence of the void parameters are correlated among these metals. The effect of helium and hydrogen gas on the void parameters is also included. The similarities and differences of the response of these materials to high dose, high temperature radiation damage are evaluated. Comparisons are made with results obtained from stainless steel and nickel base alloys. The ion bombardment data is then compared and correlated, as far as possible, with existing neutron data on the refractory metals. The theoretically calculated damage state produced by neutrons and ions is also briefly discussed and compared to experimental data wherever possible. The advantages and limitations of ion simulation in relation to fusion radiation damage are finally summarized

  12. Radiation induced crystallinity damage in poly(L-lactic acid)

    CERN Document Server

    Kantoglu, O

    2002-01-01

    The radiation-induced crystallinity damage in poly(L-lactic acid) (PLLA) in the presence of air and in vacuum, is studied. From the heat of fusion enthalpy values of gamma irradiated samples, some changes on the thermal properties were determined. To identify these changes, first the glass transition temperature (T sub g) of L-lactic acid polymers irradiated to various doses in air and vacuum have been investigated and it is found that it is independent of irradiation atmosphere and dose. The fraction of damaged units of PLLA per unit of absorbed energy has been measured. For this purpose, SAXS and differential scanning calorimetry methods were used, and the radiation yield of number of damaged units (G(-u)) is found to be 0.74 and 0.58 for PLLA samples irradiated in vacuum and air, respectively.

  13. EDGAR, a new plant radiation monitoring system

    International Nuclear Information System (INIS)

    Vuong, Q.M.; Da Costa Vieira, D.

    2004-01-01

    The EDGAR system is a new radiation monitoring system for nuclear power plant, reprocessing plant and nuclear research reactor for radioactive contamination, gamma and neutron field monitoring. Developed by French Atomic Energy Agency, this system provides not only complete functions of standard RMS, also allows spectroscopy level detection of alpha and beta particles based on a patented collimator unit. A complete computerized approach has been taken allowing full installation control in a single PC based display and communication unit. (author)

  14. Radiation damage resistance in mercuric iodide X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Patt, B E; Dolin, R C; Devore, T M; Markakis, J M [EG and G Energy Measurements, Inc., Goleta, CA (USA); Iwanczyk, J S; Dorri, N [Xsirius, Inc., Marina del Rey, CA (USA); Trombka, J [National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center

    1990-12-20

    Mercuric iodide (HgI{sub 2}) radiation detectors show great potential as ambient-temperature solid-state detectors for X-rays, gamma rays and visible light, with parameters that are competitive with existing technologies. In a previous experiment, HgI{sub 2} detectors irradiated with 10 MeV protons/cm{sup 2} exhibited no damage. The 10 MeV protons represent only the low range of the spectrum of energies that are important. An experiment has been conducted at the Saturne accelerator facility at Saclay, France, to determine the susceptibility of these detectors to radiation damage by high-energy (1.5 GeV) protons. The detectors were irradiated to a fluence of 10{sup 8} protons/cm{sup 2}. This fluence is equivalent to the cosmic radiation expected in a one-year period in space. The resolution of the detectors was measured as a function of the integral dose. No degradation in the response of any of the detectors or spectrometers was seen. It is clear from this data that HgI{sub 2} has extremely high radiation-damage resistance, exceeding that of most other semiconductor materials used for radiation detectors. Based on the results shown to date, HgI{sub 2} detectors are suitable for applications in which they may be exposed to high integral dose levels. (orig.).

  15. First Results from the Online Radiation Dose Monitoring System in ATLAS experiment

    CERN Document Server

    Mandić, I; The ATLAS collaboration; Deliyergiyev, M; Gorišek, A; Kramberger, G; Mikuž, M; Franz, S; Hartert, J; Dawson, I; Miyagawa, P; Nicolas, L

    2011-01-01

    High radiation doses which will accumulate in components of ATLAS experiment during data taking will causes damage to detectors and readout electronics. It is therefore important to continuously monitor the doses to estimate the level of degradation caused by radiation. Online radiation monitoring system measures ionizing dose in SiO2 , displacement damage in silicon in terms of 1-MeV(Si) equivalent neutron fluence and fluence of thermal neutrons at several locations in ATLAS detector. In this paper design of the system, results of measurements and comparison of measured integrated doses and fluences with predictions from FLUKA simulation will be shown.

  16. Radiation damage studies for the D0 silicon detector

    International Nuclear Information System (INIS)

    Lehner, F.

    2004-01-01

    We report on irradiation studies performed on spare production silicon detector modules for the current D0 silicon detector. The lifetime expectations due to radiation damage effects of the existing silicon detector are reviewed. A new upgrade project was started with the goal of a complete replacement of the existing silicon detector. In that context, several investigations on the radiation hardness of new prototype silicon microstrip detectors were carried out. The irradiation on different detector types was performed with 10 MeV protons up to fluences of 10 14 p/cm 2 at the J.R. Mcdonald Laboratory at Kansas State University. The flux calibration was carefully checked using different normalization techniques. As a result, we observe roughly 40-50% less radiation damage in silicon for 10 MeV p exposure than it is expected by the predicted NIEL scaling

  17. Radiation damage studies for the DOe silicon detector

    International Nuclear Information System (INIS)

    Lehner, Frank

    2004-01-01

    We report on irradiation studies performed on spare production silicon detector modules for the current DOe silicon detector. The lifetime expectations due to radiation damage effects of the existing silicon detector are reviewed. A new upgrade project was started with the goal of a complete replacement of the existing silicon detector. In that context, several investigations on the radiation hardness of new prototype silicon microstrip detectors were carried out. The irradiation on different detector types was performed with 10 MeV protons up to fluences of 10 14 p/cm 2 at the J.R. Mcdonald Laboratory at Kansas State University. The flux calibration was carefully checked using different normalisation techniques. As a result, we observe roughly 40-50% less radiation damage in silicon for 10 MeV p exposure than it is expected by the predicted NIEL scaling

  18. Temperature effects on radiation damage in plastic detectors

    International Nuclear Information System (INIS)

    Mendoza A, D.

    1996-01-01

    The objective of present work was to study the temperature effect on radiation damage registration in the structure of a Solid State Nuclear Track Detector of the type CR-39. In order to study the radiation damage as a function of irradiation temperature, sheets of CR-39 detectors were irradiated with electron beams, simulating the interaction of positive ions. CR-39 detectors were maintained at a constant temperature from room temperature up to 373 K during irradiation. Two techniques were used from analyzing changes in the detector structure: Electronic Paramagnetic Resonance (EPR) and Infrared Spectroscopy (IR). It was found by EPR analysis that the amount of free radicals decrease as irradiation temperature increases. The IR spectrums show yield of new functional group identified as an hydroxyl group (OH). A proposed model of interaction of radiation with CR-39 detectors is discussed. (Author)

  19. Ultra Secure High Reliability Wireless Radiation Monitor

    International Nuclear Information System (INIS)

    Cordaro, J.; Shull, D.; Farrar, M.; Reeves, G.

    2011-01-01

    Radiation monitoring in nuclear facilities is essential to safe operation of the equipment as well as protecting personnel. In specific, typical air monitoring of radioactive gases or particulate involves complex systems of valves, pumps, piping and electronics. The challenge is to measure a representative sample in areas that are radioactively contaminated. Running cables and piping to these locations is very expensive due to the containment requirements. Penetration into and out of an airborne or containment area is complex and costly. The process rooms are built with thick rebar-enforced concrete walls with glove box containment chambers inside. Figure 1 shows high temperature radiation resistance cabling entering the top of a typical glove box. In some case, the entire processing area must be contained in a 'hot cell' where the only access into the chamber is via manipulators. An example is shown in Figure 2. A short range wireless network provides an ideal communication link for transmitting the data from the radiation sensor to a 'clean area', or area absent of any radiation fields or radioactive contamination. Radiation monitoring systems that protect personnel and equipment must meet stringent codes and standards due to the consequences of failure. At first glance a wired system would seem more desirable. Concerns with wireless communication include latency, jamming, spoofing, man in the middle attacks, and hacking. The Department of Energy's Savannah River National Laboratory (SRNL) has developed a prototype wireless radiation air monitoring system that address many of the concerns with wireless and allows quick deployment in radiation and contamination areas. It is stand alone and only requires a standard 120 VAC, 60 Hz power source. It is designed to be mounted or portable. The wireless link uses a National Security Agency (NSA) Suite B compliant wireless network from Fortress Technologies that is considered robust enough to be used for classified data

  20. ULTRA SECURE HIGH RELIABILITY WIRELESS RADIATION MONITOR

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, J.; Shull, D.; Farrar, M.; Reeves, G.

    2011-08-03

    Radiation monitoring in nuclear facilities is essential to safe operation of the equipment as well as protecting personnel. In specific, typical air monitoring of radioactive gases or particulate involves complex systems of valves, pumps, piping and electronics. The challenge is to measure a representative sample in areas that are radioactively contaminated. Running cables and piping to these locations is very expensive due to the containment requirements. Penetration into and out of an airborne or containment area is complex and costly. The process rooms are built with thick rebar-enforced concrete walls with glove box containment chambers inside. Figure 1 shows high temperature radiation resistance cabling entering the top of a typical glove box. In some case, the entire processing area must be contained in a 'hot cell' where the only access into the chamber is via manipulators. An example is shown in Figure 2. A short range wireless network provides an ideal communication link for transmitting the data from the radiation sensor to a 'clean area', or area absent of any radiation fields or radioactive contamination. Radiation monitoring systems that protect personnel and equipment must meet stringent codes and standards due to the consequences of failure. At first glance a wired system would seem more desirable. Concerns with wireless communication include latency, jamming, spoofing, man in the middle attacks, and hacking. The Department of Energy's Savannah River National Laboratory (SRNL) has developed a prototype wireless radiation air monitoring system that address many of the concerns with wireless and allows quick deployment in radiation and contamination areas. It is stand alone and only requires a standard 120 VAC, 60 Hz power source. It is designed to be mounted or portable. The wireless link uses a National Security Agency (NSA) Suite B compliant wireless network from Fortress Technologies that is considered robust enough to be

  1. Introduction to neutron metrology for reactor radiation damage

    International Nuclear Information System (INIS)

    Alberman, A.; Genthon, J.P.; Wright, S.B.; Zijp, W.L.

    1977-01-01

    This document, prepared by members of the Irradiation Damage Subgroup of the Euratom Working Group on Reactor Dosimetry (EWGRD) describes the background of the procedures for determining irradiation parameters which are of interest in radiation damage experiments. The first two chapters outline the concept of damage functions and damge models. The next two chapters give information on methods to determine neutron fluences and neutron spectra. The fifth chapter gives a review of correlation data available for graphite and steels. The last chapter gives guidance how to report the relevant irradiation parameters. Attention is given to the role of the neutron spectrum in deriving values for damage fluence, energy transferred to the lattice, and number of displacements. A suggested list to report data relevant to the irradiation, the instrumentation and the testing of material is included

  2. Radiation damage in A-15 materials: EXAFS studies

    International Nuclear Information System (INIS)

    Knapp, G.S.; Kampwirth, R.T.; Georgopoulos, P.; Brown, B.S.

    1980-01-01

    EXAFS measurements are useful in determining the local atomic environment of a particular element in a solid. Since there has been some controversy about the nature of the defects produced in A-15 materials by radiation damage, such studies were carried out on some A-15 compounds, V 3 Ga which was damaged by neutrons, as well as Nb 3 Ge damaged by 2.5 MeV a particles. In the V 3 Ga sample, site exchange disorder seems to be the most important result of the neutron damage with less than 20% of the vanadium atoms on wrong sites. However, in the Nb 3 Ge samples in addition to site exchange disorder, an unusual splitting of the first near-neighbor distance between the Ge and Nb is found. This splitting, approximately 0.2 A, may explain the large Debye Waller factors observed by Burbank et al

  3. Radiation monitoring considerations for radiobiology facilities

    International Nuclear Information System (INIS)

    McClelland, T.W.; McFall, E.D.

    1976-01-01

    Battelle, Pacific Northwest Laboratories, conducts a wide variety of radiobiology and radioecology research in a number of facilities on the Hanford Reservation. Review of radiation monitoring problems associated with storage, plant and animal experiments, waste handling and sterile facilities shows that careful monitoring, strict procedural controls and innovative techniques are required to minimize occupational exposure and control contamination. Although a wide variety of radioactivity levels are involved, much of the work is with extremely low level materials. Monitoring low level work is mundane and often impractical but cannot be ignored in today's ever tightening controls

  4. Method and apparatus for neutron radiation monitoring

    International Nuclear Information System (INIS)

    Schwarzmann, A.

    1985-01-01

    A self-calibrated neutron radiation monitor includes a flux responsive element comprised of intrinsic silicon neutron detectors and self-calibration resistors in a single structure. As the resistance of the flux responsive element increases to the value of successive calibration resistors, known increments of flux have been encountered

  5. Compilation of radiation damage test data. Pt. 3

    International Nuclear Information System (INIS)

    Beynel, P.; Maier, P.; Schoenbacher, H.

    1982-01-01

    This handbook gives the results of radiation damage tests on various engineering materials and components intended for installation in radiation areas of the CERN high-energy particle accelerators. It complements two previous volumes covering organic cable-insulating materials and thermoplastic and thermosetting resins. The irradiation have been carried out at various radiation sources and the results of the different tests are reported, sometimes illustrated by tables and graphs to show the variation of the measured property with absorbed radiation dose. For each entry, an appreciation of the radiation resistance is given, based on measurement data, indicating the range of damage (moderate to severe) for doses from 10 to 10 8 Gy. Also included are tables, selected from published reports, of general relative radiation effects for several groups of materials, to which there are systematic cross-references in the alphabetical part. This third and last volume contains cross-references to all the materials presented up to now, so that it can be used as a guide to the three volumes. (orig.)

  6. Radiation safety assessment and development of environmental radiation monitoring technology

    CERN Document Server

    Choi, B H; Kim, S G

    2002-01-01

    The Periodic Safety Review(PSR) of the existing nuclear power plants is required every ten years according to the recently revised atomic energy acts. The PSR of Kori unit 1 and Wolsong unit 1 that have been operating more than ten years is ongoing to comply the regulations. This research project started to develop the techniques necessary for the PSR. The project developed the following four techniques at the first stage for the environmental assessment of the existing plants. 1) Establishment of the assessment technology for contamination and accumulation trends of radionuclides, 2) alarm point setting of environmental radiation monitoring system, 3) Development of Radiation Safety Evaluation Factor for Korean NPP, and 4) the evaluation of radiation monitoring system performance and set-up of alarm/warn set point. A dynamic compartment model to derive a relationship between the release rates of gas phase radionuclides and the concentrations in the environmental samples. The model was validated by comparing ...

  7. Thermal annealing of natural, radiation-damaged pyrochlore

    Energy Technology Data Exchange (ETDEWEB)

    Zietlow, Peter; Mihailova, Boriana [Hamburg Univ. (Germany). Dept. of Earth Sciences; Beirau, Tobias [Hamburg Univ. (Germany). Dept. of Earth Sciences; Stanford Univ., CA (United States). Dept. of Geological Sciences; and others

    2017-03-01

    Radiation damage in minerals is caused by the α-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400-1000 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia [6.4 wt% Th, 23.1.10{sup 18} α-decay events per gram (dpg)], Panda Hill/Tanzania (1.6 wt% Th, 1.6.10{sup 18} dpg), and Blue River/Canada (10.5 wt% U, 115.4.10{sup 18} dpg), are compared with a crystalline reference pyrochlore from Schelingen (Germany). The type of structural recovery depends on the initial degree of radiation damage (Panda Hill 28%, Blue River 85% and Miass 100% according to XRD), as the recrystallization temperature increases with increasing degree of amorphization. Raman spectra indicate reordering on the local scale during annealing-induced recrystallization. As Raman modes around 800 cm{sup -1} are sensitive to radiation damage (M. T. Vandenborre, E. Husson, Comparison of the force field in various pyrochlore families. I. The A{sub 2}B{sub 2}O{sub 7} oxides. J. Solid State Chem. 1983, 50, 362, S. Moll, G. Sattonnay, L. Thome, J. Jagielski, C. Decorse, P. Simon, I. Monnet, W. J. Weber, Irradiation damage in Gd{sub 2}Ti{sub 2}O{sub 7} single crystals: Ballistic versus ionization processes. Phys. Rev. 2011, 84, 64115.), the degree of local order was deduced from the ratio of the integrated intensities of the sum of the Raman bands between 605 and 680 cm{sup -1} divided by the sum of the integrated intensities of the bands between 810 and 860 cm{sup -1}. The most radiation damaged pyrochlore (Miass) shows an abrupt recovery of both, its short- (Raman) and long-range order (X-ray) between 800 and 850 K, while the weakly damaged pyrochlore (Panda Hill) begins to recover at considerably lower temperatures (near 500 K

  8. Background compensation for a radiation level monitor

    Science.gov (United States)

    Keefe, D.J.

    1975-12-01

    Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

  9. Radiation damage in natural materials: implications for radioactive waste forms

    International Nuclear Information System (INIS)

    Ewing, R.C.

    1981-01-01

    The long-term effect of radiation damage on waste forms, either crystalline or glass, is a factor in the evaluation of the integrity of waste disposal mediums. Natural analogs, such as metamict minerals, provide one approach for the evaluaton of radiation damage effects that might be observed in crystalline waste forms, such as supercalcine or synroc. Metamict minerals are a special class of amorphous materials which were initially crystalline. Although the mechanism for the loss of crystallinity in these minerals (mostly actinide-containing oxides and silicates) is not clearly understood, damage caused by alpha particles and recoil nuclei is critical to the metamictization process. The study of metamict minerals allows the evaluation of long-term radiation damage effects, particularly changes in physical and chemical properties such as microfracturing, hydrothermal alteration, and solubility. In addition, structures susceptible to metamictization share some common properties: (1) complex compositions; (2) some degree of covalent bonding, instead of being ionic close-packed MO/sub x/ structures; and (3) channels or interstitial voids which may accommodate displaced atoms or absorbed water. On the basis of these empirical criteria, minerals such as pollucite, sodalite, nepheline and leucite warrant careful scrutiny as potential waste form phases. Phases with the monazite or fluorite structures are excellent candidates

  10. Monitoring System For Improving Radiation Safety Management

    International Nuclear Information System (INIS)

    Osovizky, A.; Paran, J.; Tal, N.; Ankry, N.; Ashkenazi, B.; Tirosh, D.; Marziano, R.; Chisin, R.

    1999-01-01

    Medi SMARTS (Medical Survey Mapping Automatic Radiation Tracing System), a gamma radiation monitoring system, was installed in a nuclear medicine department. In this paper the evaluation of the system's ability to improve radiation safety management is presented. The system is based on a state of the art software that continuously collects on line radiation measurements for display, analysis and logging. Radiation is measured by GM tubes; the signal is transferred to a data processing unit and then via an RS-485 communication line to a computer. The system automatically identifies the detector type and its calibration factor, thus providing compatibility, maintainability and versatility when changing detectors. Radiation levels are displayed on the nuclear medicine department map at six locations. The system has been operating continuously for more than one year, documenting abnormal events caused by routine operation or failure incidents. In cases where abnormal working conditions were encountered, an alarm message was sent automatically to the supervisor via his tele-pager. An interesting issue observed during the system evaluation, was the inability to distinguish between high radiation levels caused by proper routine operation and those caused by safety failure incidents. The solution included examination of two parameters, radiation levels as well as their duration period. A careful analysis of the historical data, applying the appropriated combined parameters determined for each location, verified that such a system can identify abnormal events, provide alarms to warn in case of incidents and improve standard operating procedures

  11. Radiation monitoring instrumentation for nuclear power plants

    International Nuclear Information System (INIS)

    Bharath Kumar, M.

    2013-01-01

    Measurement of nucleonic signals is required to control and operate the reactor in a safe and reliable manner. To achieve this, parameters like Neutron flux, other radiation fields, contamination levels, source strength, release thru stack etc. are required to be monitored and controlled. The above are required to be monitored throughout the life of the reactor whether it is operational or in shutdown condition. In addition such monitoring is also required during decommissioning phase of the reactor as needed. To measure these parameters a large number of instruments are used in Nuclear Power Plants (NPP) which includes sensors and electronics for detecting alpha, beta, gamma and neutron radiation with qualification to withstand harsh environment

  12. Multiscale approach to the physics of radiation damage with ions

    International Nuclear Information System (INIS)

    Surdutovich, E.; Solov'yov, A.

    2014-01-01

    The multiscale approach to the assessment of bio-damage resulting upon irradiation of biological media with ions is reviewed, explained and compared to other approaches. The processes of ion propagation in the medium concurrent with ionization and excitation of molecules, transport of secondary products, dynamics of the medium, and biological damage take place on a number of different temporal, spatial and energy scales. The multiscale approach, a physical phenomenon-based analysis of the scenario that leads to radiation damage, has been designed to consider all relevant effects on a variety of scales and develop an approach to the quantitative assessment of biological damage as a result of irradiation with ions. Presently, physical and chemical effects are included in the scenario while the biological effects such as DNA repair are only mentioned. This paper explains the scenario of radiation damage with ions, overviews its major parts, and applies the multiscale approach to different experimental conditions. On the basis of this experience, the recipe for application of the multiscale approach is formulated. The recipe leads to the calculation of relative biological effectiveness. (authors)

  13. Positron annihilation lifetime study of radiation-damaged natural zircons

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, J. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra (Australia); Gaugliardo, P. [Centre for Antimatter-Matter Studies, School of Physics, University of Western Australia (Australia); Farnan, I.; Zhang, M. [Department of Earth Sciences, University of Cambridge (United Kingdom); Vance, E.R.; Davis, J.; Karatchevtseva, I.; Knott, R.B. [Australian Nuclear Science and Technology Organisation (Australia); Mudie, S. [The Australian Synchrotron, Victoria (Australia); Buckman, S.J. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra (Australia); Institute for Mathematical Sciences, University of Malaya, Kuala Lumpur (Malaysia); Sullivan, J.P., E-mail: james.sullivan@anu.edu.au [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra (Australia)

    2016-04-01

    Zircons are a well-known candidate waste form for actinides and their radiation damage behaviour has been widely studied by a range of techniques. In this study, well-characterised natural single crystal zircons have been studied using Positron Annihilation Lifetime Spectroscopy (PALS). In some, but not all, of the crystals that had incurred at least half of the alpha-event damage of ∼10{sup 19} α/g required to render them structurally amorphous, PALS spectra displayed long lifetimes corresponding to voids of ∼0.5 nm in diameter. The long lifetimes corresponded to expectations from published Small-Angle X-ray Scattering data on similar samples. However, the non-observation by PALS of such voids in some of the heavily damaged samples may reflect large size variations among the voids such that no singular size can be distinguished or. Characterisation of a range of samples was also performed using scanning electron microscopy, optical absorption spectroscopy, Raman scattering and X-ray scattering/diffraction, with the degree of alpha damage being inferred mainly from the Raman technique and X-ray diffraction. The observed void diameters and intensities of the long lifetime components were changed somewhat by annealing at 700 °C; annealing at 1200 °C removed the voids entirely. The voids themselves may derive from He gas bubbles or voids created by the inclusion of small quantities of organic and hydrous matter, notwithstanding the observation that no voidage was evidenced by PALS in two samples containing hydrous and organic matter. - Highlights: • Study of a range of naturally occurring zircons damaged by alpha radiation. • Characterised using a range of techniques, including PALS spectroscopy. • Effects on hydrous material appear important, rather than direct radiation damage. • Annealing is shown to remove the observed voids.

  14. Smarter radiation monitors for safeguards and security

    International Nuclear Information System (INIS)

    Fehlau, P.E.; Pratt, J.C.; Markin, J.T.; Scurry, T. Jr.

    1983-01-01

    Radiation monitors for nuclear safeguards and security depend on internal control circuits to determine when diversion of special nuclear materials is taking place. Early monitors depended on analog circuits for this purpose, subsequently, digital logic controllers made better monitoring methods possible. Now, versatile microprocessor systems permit new, more efficient, and more useful monitoring methods. One such method is simple stepwise monitoring, which has variable alarm levels to expedite monitoring where extended monitoring periods are required. Another method, sequential probability ratio logic, tests data as it accumulates against two hypothesis - background, or background plus a transient diversion signal - and terminates monitoring as soon as a decision can be made that meets false-alarm and detection confidence requirements. A third method, quantitative monitoring for personnel, calculates count ratios of high- to low-energy gamma-ray regions to predict whether the material detected is a small quantity of bare material or a larger quantity of shielded material. In addition, microprocessor system subprograms can assist in detector calibration and trouble-shooting. Examples of subprograms are a variance analysis technique to set bias levels in plastic scintillators and a state-of-health routine for detecting malfunctions in digital circuit components

  15. Radiation-induced Pulmonary Damage in Lung Cancer Patients

    International Nuclear Information System (INIS)

    Chung, Su Mi; Choi, Ihl Bohng; Kang, Mi Mun; Kim, In Ah; Shinn, Kyung Sub

    1993-01-01

    Purpose: A retrospective analysis was performed to evaluate the incidence of radiation induced lung damage after the radiation therapy for the patients with carcinoma of the lung. Method and Materials: Sixty-six patients with lung cancer (squamous cell carcinoma 27, adenocarcinoma 14, large cell carcinoma 2, small cell carcinoma 13, unknown 10) were treated with definitive, postoperative or palliative radiation therapy with or without chemotherapy between July 1987 and December 1991. There were 50 males and 16 females with median age of 63 years(range: 33-80 years). Total lung doses ranged from 500 to 6,660 cGy (median 3960 cGy) given in 2 to 38 fractions (median 20) over a range of 2 to 150 days (median 40 days) using 6 MV or 15 MV linear accelerator. To represent different fractionation schedules of equivalent biological effect, the estimated single dose(ED) model, ED=D·N-0.377·T-0.058 was used in which D was the lung dose in cGy, N was the number of fractions, and T was the overall treatment time in days. The range of ED was 370 to 1357. The endpoint was a visible increase in lung density within the irradiated volume on chest X-ray as observed independently by three diagnostic radiologists. Patients were grouped according to ED, treatment duration, treatment modality and age, and the percent incidence of pulmonary damage for each group was determined. Result: In 40 of 66 patients, radiation induced change was seen on chest radiographs between 11 days and 314 days after initiation of radiation therapy. The incidence of radiation pneumonitis was increased according to increased ED, which was statistically significant (p=0.001). Roentgenographic charges consistent with radiation pneumonitis were seen in 100% of patients receiving radiotherapy after lobectomy or pneumonectomy, which was not statistically significant. In 32 patients who also received chemotherapy, there was no difference in the incidence of radiation induced charge between the group with radiation

  16. Radiation damage in CaF2: Gd

    International Nuclear Information System (INIS)

    Prado, L.

    1979-01-01

    Calcium fluoride crystals doped with Gd 3+ at four different concentrations were irradiated at room temperature. The damage produced by radiation and the primary and secondary effects as well were studied by optical spectroscopy. The increase in optical absorption (with loss of transparency) varied from sample as a function of concentration and dose. The coloration curves showed an evolution from two to three radiation damage steps when going from a pure to the most Gd 3+ concentrated sample. The obtained spectra were analysed at characteristic wave lenghts of electronic defects (photochromic centers, F and its aggregates) and of Gd 3+ and Gd 2+ defects. As a result of the radiation damage the valence change (Gd 3+ →Gd 2+ ) and its reversible character under thermal activation were directly observed. These effects were correlated with other observed effects such as the room temperature luminescence after the irradiation ceased. The non radiative F centers formation from the interaction of holes and photochromic centers was also observed and analysed. A thermal activation study of the several defects responsible for the different absorption bands was made. Values of activation energies were obtained as expected for the kind of defects involved in these processes [pt

  17. Laser annealing heals radiation damage in avalanche photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jin Gyu [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); Anisimova, Elena; Higgins, Brendon L.; Bourgoin, Jean-Philippe [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Jennewein, Thomas [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Canadian Institute for Advanced Research, Quantum Information Science Program, Toronto, ON (Canada); Makarov, Vadim [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada)

    2017-12-15

    Avalanche photodiodes (APDs) are a practical option for space-based quantum communications requiring single-photon detection. However, radiation damage to APDs significantly increases their dark count rates and thus reduces their useful lifetimes in orbit. We show that high-power laser annealing of irradiated APDs of three different models (Excelitas C30902SH, Excelitas SLiK, and Laser Components SAP500S2) heals the radiation damage and several APDs are restored to typical pre-radiation dark count rates. Of nine samples we test, six APDs were thermally annealed in a previous experiment as another solution to mitigate the radiation damage. Laser annealing reduces the dark count rates further in all samples with the maximum dark count rate reduction factor varying between 5.3 and 758 when operating at -80 C. This indicates that laser annealing is a more effective method than thermal annealing. The illumination power to reach these reduction factors ranges from 0.8 to 1.6 W. Other photon detection characteristics, such as photon detection efficiency, timing jitter, and afterpulsing probability, fluctuate but the overall performance of quantum communications should be largely unaffected by these variations. These results herald a promising method to extend the lifetime of a quantum satellite equipped with APDs. (orig.)

  18. Primary radiation damage and disturbance in cell divisions

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Lee, Yun-Jong; Kim, Jae-Hun; Petin, Vladislav G.; Nili, Mohammad

    2008-01-01

    Survived cells from a homogeneous population exposed to ionizing radiation form various colonies of different sizes and morphology on a solid nutrient medium, which appear at different time intervals after irradiation. Such a phenomenon agrees well with the modern theory of microdosimetry and classical hit-and-target models of radiobiology. According to the hit-principle, individual cells exposed to the same dose of radiation are damaged in different manners. It means that the survived cells can differ in the content of sublethal damage (hits) produced by the energy absorbed into the cell and which is not enough to give rise to effective radiation damage which is responsible for cell killing or inactivation. In diploid yeast cells, the growth rate of cells from 250 colonies of various sizes appeared at different time intervals after irradiation with 600 Gy of gamma radiation from a 60 Co isotopic source was analyzed. The survival rate after irradiation was 20%. Based on the analyses results, it was possible to categorize the clones grown from irradiated cells according to the number of sub-lesions from 1 to 4. The clones with various numbers of sub-lesions were shown to be different in their viability, radiosensitivity, sensitivity to environmental conditions, and the frequency of recombination and respiratory deficient mutations. Cells from unstable clones exhibited an enhanced radiosensitivity, and an increased portion of morphologically changed cells, nonviable cells and respiration mutants, as well. The degree of expression of the foregoing effects was higher if the number of primary sublethal lesions was greater in the originally irradiated cell. Disturbance in cell division can be characterized by cell inactivation or incorrect distribution of mitochondria between daughter cells. Thus, the suggested methodology of identification of cells with a definite number of primary sublethal lesions will promote further elucidation of the nature of primary radiation

  19. Consequential late radiation damage in the skin in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Li Wei; Kong Ling; Zhang Youwang; Hu Chaosu; Wu Yongru

    2008-01-01

    Objective: To evaluate the relationship between early and late radiation damage in skin. Methods: 335 patients with nasopharyngeal carcinoma treated with radical radiotherapy were evaluated. 240 patients had lymph nodes in the neck at initial diagnosis. The median doses were 70 Gy (55-86 Gy) to the nasopharyngeal region by external beam radiotherapy. The median doses were 64 Gy (46-72 Gy) to the neck with lymph node metastases, 55 Gy (21-67 Gy) to the node-negative neck. 71 patients were treated with facial-neck fields, while 264 patients were treated with pre-auricular fields. Chemotherapy was given in 48 patients. According to the 1995 SOMA scales late radiation damage in the skin was evaluated. Results: The median time from the radiotherapy to follow up was 14 years (range, 5-38 years). 63 patients have grade 0 late radiation reactions in the neck skin, the grade 1,2, 3,4 late radiation reactions in the neck skin were 43.9% (147 patients), 20.9% (70 patients), 13.7% (46 patients) and 2.7% (9 patients), respectively. 44 patients had moist desquamation in the medical records. The grade 1,2,3,4 late radiation reactions in the neck skin were 41%, 23%, 30% and 5%, respectively in patients with moist desquamation, while in patients without moist desquamation, the corresponding rates were 44.3%, 20.6%, 11.3% and 2.4%, respectively. The difference were significant between these two groups by chi-square analysis(χ 2 =17.42, P=0.002). Furthermore, whether patients had positive lymph node in the neck or not, the size of facial-neck fields and higher doses to the neck had more severe late radiation reaction in the neck skin, while age, gender and chemotherapy failed to show any effects on the development of late radiation reactions in the neck skin. Conclusion: The severe early radiation damage in the skin possibly increases the late radiation damage in the neck skin. (authors)

  20. Measuring Radiation Damage from Heavy Energetic Ions in Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kostin, M., PI-MSU; Ronningen, R., PI-MSU; Ahle, L., PI-LLNL; Gabriel, T., Scientific Investigation and Development; Mansur, L., PI-ORNL; Leonard, K., ORNL; Mokhov, N., FNAL; Niita, K., RIST, Japan

    2009-02-21

    An intense beam of 122 MeV/u (9.3 GeV) 76Ge ions was stopped in aluminum samples at the Coupled Cyclotron Facility at NSCL, MSU. Attempts were made at ORNL to measure changes in material properties by measuring changes in electrical resistivity and microhardness, and by transmission electron microscopy characterization, for defect density caused by radiation damage, as a function of depth and integrated ion flux. These measurements are relevant for estimating damage to components at a rare isotope beam facility.

  1. Genetic damage from low-level and natural background radiation

    International Nuclear Information System (INIS)

    Oftedal, P.

    1988-01-01

    Relevant predictions that have been made of possible low level biological effects on man are reviewed, and the estimate of genetic damage is discussed. It is concluded that in spite of a number of attempts, no clear-cut case of effects in human populations of radiation at natural levels has been demonstrated. The stability of genetic material is dynamic, with damage, repair and selection running as continuous processes. Genetic materials are well protected and are conservative in the extreme, not least because evolution by genetic adaptation is an expensive process: Substitution of one allele A 1 by another A 2 means the death of the whole A 1 population

  2. Development and anneal of radiation damage in salt

    International Nuclear Information System (INIS)

    Garcia Celma, A.; Donker, H.; Soppe, W.J.; Miralles, L.

    1993-12-01

    Laboratory gamma-irradiations at a constant temperature (100 C) were carried out in two sorts of experiments, one at variable and another at approximately constant dose rates. The damage developed during irradiation was analyzed by thermal analysis, microstructural analysis and small angle neutron scattering. The results were compared with the yields of the Jain-Lidiard model for each experiment. Experiments at a constant dose rate were planned to obtain information on radiation damage development and anneal in conditions as near as possible to those of radioactive waste repository concepts. For this reason the dose rates were kept low. (orig./DG)

  3. Radiation monitoring data representation for duty personnel

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, S.L.; Kiselev, V.P.; Krasnoperov, S.N.; Kudeshov, E.V.; Maslov, S.Y.; Semin, N.N.; Sirotinskiy, S.E.; Yakovlev, V.Y. [Nuclear Safety Institute of the Russian Academy of Sciences (NSI RAS), Moscow (Russian Federation)

    2014-07-01

    Currently, Web-GIS technologies are widely used to generate a reliable and intuitive web-based interface to monitor the current radiation situation in various regions of the Russian Federation. The developed 'Server Web-Monitoring' web-application is intended for duty personnel and can operate not only on desktop computers but also on mobile devices. The subsystem of duty personnel notification about any Off-Normal Situation (ONS) (such as: critical threshold exceedances or failures in operation of monitoring systems) is also considered in the paper. Three types of Automated Radiation Monitoring Systems (ARMS) are available for monitoring: - regional ARMS; - facility-level ARMS; - ARMS of nuclear power plant surveillance areas. Google Maps and Google Maps API toolbox are used as the cartographic basis. In the general-monitoring window only general information on each of the local systems is available. Next, the operator can move to monitoring of local ARMS he is interested in. The operator can either view a list of Radiation Situation Monitoring Posts (RSMP) showing the current data in the right frame or hide it and use the map only. Viewing the log of critical threshold exceedances for 24 hours and a report on all RSMPs of a given system over the last 7 days is also possible. The report contains maximum values of measurements for every day and for each RSMP. The developed web-application includes: - monitoring of the radiation situation and its changes on the general map of the Russian Federation and on maps of local ARMS; - displaying 7-day reports for all RSMPs of the selected ARMS; - displaying the log of critical threshold exceedances recorded over the past day. The notification subsystem informs duty personnel on all ONS, namely, on critical threshold exceedances in the incoming data and failures in operation of monitoring systems. The key features of the notification subsystem are: - round-the-clock functioning; - automatic notification in case of

  4. Action of the chlorophyllin on the genetic damage induced by gamma radiation in germinal cells of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Cruces, M.P.; Pimentel, A.E.; Moreno, A.; Moreno, R.

    2003-01-01

    The obtained results using somatic cells, they have evidenced that the chlorophyllin (CHLN) it can act inhibiting or increasing the damage caused by different mutagens. The objective of this investigation is to evaluate the effect of the CHLN on the damage induced by gamma radiation in germinal cells of Drosophila. Two tests were used, the lost of the X chromosome and the conventional test of lethal recessive bound to the sex (LRLS); both with a system of litters. The obtained results in both essays, indicated that the CHLN doesn't reduce the damage induced by the gamma radiation in none of the cellular monitored states. (Author)

  5. Radiation monitor for surveillance of moving vehicles

    International Nuclear Information System (INIS)

    Dvorak, R.F.

    1985-09-01

    A radiation monitor has been developed that will scan each vehicle leaving the Clinton P. Anderson Los Alamos Meson Physics Facility site. If an increase in radiation level is sensed, an alarm light and a Klaxon horn are activated, inviting the driver to return to the Health Physics office for check. A photograph showing the vehicle license number is also taken. A radiation source that doubles the detector count rate when stationary will cause an alarm at vehicle speeds up to about 24 km/h (15 mph). The technique used to prevent false alarms because of radiations from nearby buildings or from plumes of low-level radioactive gas is described. 9 figs

  6. Environmental radiation monitoring around the nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Woo

    2012-03-15

    Environmental Radiation Monitoring was carried out with measurement of environment. radiation and environmental radioactivity analysis on the sites of KAERI nuclear facilities and Seoul Research Reactors and their environments. The average level of environmental radiation dose measured by an ERM and the accumulated radiation dose by a TLD were almost same level compared with the previous years. The activity of gross {alpha} and gross {beta}, Tritium, Uranium and Strontium in environmental samples showed a environmental level. The {gamma}-radionuclides such as natural radionuclides 40K or 7Be were detected in pine needle and food. The nuclear radionuclides 134Cs, 137Cs or 131I were temporarily detected in the samples of air particulate and rain in April and of fall out in 2nd quarter from the effect of Fukusima accident.

  7. Environmental Radiation Monitoring Around the Nuclear Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Geun Sik; Lee, Chang Woo

    2008-05-15

    Environmental Radiation Monitoring was carried out with measurement of environment. radiation and environmental radioactivity analysis on the sites of KAERI nuclear facilities and Seoul Research Reactors and their environments. The average level of environmental radiation dose measured by an ERM and the accumulated radiation dose by a TLD were almost same level compared with the previous years. The activity of gross {alpha} and gross {beta}, Tritium, Uraniu and Strontium in environmental samples showed a environmental level. The radioactivities of most {gamma}-radionuclides in air particulate, surface water and ground water were less than MDA except {sup 40}K or {sup 7}Be which are natural radionuclides. However, not only {sup 40}K or {sup 7}Be but also {sup 137}Cs were detected at the background level in surface soil, discharge sediment and fallout or pine needle.

  8. Radiation survey meters used for environmental monitoring

    International Nuclear Information System (INIS)

    Bjerke, H.; Sigurdsson, T.; Meier Pedersen, K.; Grindborg, J.-E.; Persson, L.; Siiskonen, T.; Hakanen, A.; Kosunen, A.

    2012-01-01

    The Nordic dosimetry group set up the GammaRate project to investigate how its expertise could be used to assure appropriate usage of survey meters in environmental monitoring. Considerable expertise in calibrating radiation instruments exists in the Nordic radiation protection authorities. The Swedish, Finnish, Danish and Norwegian authorities operate Secondary Standard Dosimetry Laboratories (SSDLs) that provide users with calibration traceable to internationally recognised primary standards. These authorities together with the Icelandic authorities have formally cooperated since 2002 in the field of radiation dosimetry. Dosimetry is the base for assesment of risk from ionising radiation and calibration of instruments is an imported part in dosimetry. The Nordic dosimetry group has been focused on cancer therapy. This work extends the cooperation to the dosimetry of radiation protection and environmental monitoring. This report contains the formal, theoretical and practical background for survey meter measurements. Nordic standards dosimetry laboratories have the capability to provide traceable calibration of instruments in various types of radiation. To verify and explore this further in radiation protection applications a set of survey instruments were sent between the five Nordic countries and each of the authority asked to provide a calibration coefficient for all instruments. The measurement results were within the stated uncertainties, except for some results from NRPA for the ionchamber based instrument. The comparison was shown to be a valuable tool to harmonize the calibration of radiation protection instruments in the Nordic countries. Dosimetry plays an important role in the emergency situations, and it is clear that better traceability and harmonised common guidelines will improve the emergency preparedness and health. (Author)

  9. Radiation survey meters used for environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bjerke, H. (ed.) (Norwegian Radiation Protection Authority, NRPA (Norway)); Sigurdsson, T. (Icelandic Radiation Safety Authority, Geislavarnir Rikisins, GR (IS)); Meier Pedersen, K. (National Board of Health, Statens Institut for Straalebeskyttelse (SIS) (Denmark)); Grindborg, J.-E.; Persson, L. (Swedish Radiation Safety Authority, Straalsaekerhetsmyndigheten (SSM) (Sweden)); Siiskonen, T.; Hakanen, A.; Kosunen, A. (Radiation and Nuclear Safety Authority, Saeteilyturvakeskus (STUK) (Finland))

    2012-01-15

    The Nordic dosimetry group set up the GammaRate project to investigate how its expertise could be used to assure appropriate usage of survey meters in environmental monitoring. Considerable expertise in calibrating radiation instruments exists in the Nordic radiation protection authorities. The Swedish, Finnish, Danish and Norwegian authorities operate Secondary Standard Dosimetry Laboratories (SSDLs) that provide users with calibration traceable to internationally recognised primary standards. These authorities together with the Icelandic authorities have formally cooperated since 2002 in the field of radiation dosimetry. Dosimetry is the base for assesment of risk from ionising radiation and calibration of instruments is an imported part in dosimetry. The Nordic dosimetry group has been focused on cancer therapy. This work extends the cooperation to the dosimetry of radiation protection and environmental monitoring. This report contains the formal, theoretical and practical background for survey meter measurements. Nordic standards dosimetry laboratories have the capability to provide traceable calibration of instruments in various types of radiation. To verify and explore this further in radiation protection applications a set of survey instruments were sent between the five Nordic countries and each of the authority asked to provide a calibration coefficient for all instruments. The measurement results were within the stated uncertainties, except for some results from NRPA for the ionchamber based instrument. The comparison was shown to be a valuable tool to harmonize the calibration of radiation protection instruments in the Nordic countries. Dosimetry plays an important role in the emergency situations, and it is clear that better traceability and harmonised common guidelines will improve the emergency preparedness and health. (Author)

  10. High and Low LET Radiation Differentially Induce Normal Tissue Damage Signals

    International Nuclear Information System (INIS)

    Niemantsverdriet, Maarten; Goethem, Marc-Jan van; Bron, Reinier; Hogewerf, Wytse; Brandenburg, Sytze; Langendijk, Johannes A.; Luijk, Peter van; Coppes, Robert P.

    2012-01-01

    Purpose: Radiotherapy using high linear energy transfer (LET) radiation is aimed at efficiently killing tumor cells while minimizing dose (biological effective) to normal tissues to prevent toxicity. It is well established that high LET radiation results in lower cell survival per absorbed dose than low LET radiation. However, whether various mechanisms involved in the development of normal tissue damage may be regulated differentially is not known. Therefore the aim of this study was to investigate whether two actions related to normal tissue toxicity, p53-induced apoptosis and expression of the profibrotic gene PAI-1 (plasminogen activator inhibitor 1), are differentially induced by high and low LET radiation. Methods and Materials: Cells were irradiated with high LET carbon ions or low LET photons. Cell survival assays were performed, profibrotic PAI-1 expression was monitored by quantitative polymerase chain reaction, and apoptosis was assayed by annexin V staining. Activation of p53 by phosphorylation at serine 315 and serine 37 was monitored by Western blotting. Transfections of plasmids expressing p53 mutated at serines 315 and 37 were used to test the requirement of these residues for apoptosis and expression of PAI-1. Results: As expected, cell survival was lower and induction of apoptosis was higher in high -LET irradiated cells. Interestingly, induction of the profibrotic PAI-1 gene was similar with high and low LET radiation. In agreement with this finding, phosphorylation of p53 at serine 315 involved in PAI-1 expression was similar with high and low LET radiation, whereas phosphorylation of p53 at serine 37, involved in apoptosis induction, was much higher after high LET irradiation. Conclusions: Our results indicate that diverse mechanisms involved in the development of normal tissue damage may be differentially affected by high and low LET radiation. This may have consequences for the development and manifestation of normal tissue damage.

  11. Protection from ionizing radiation induced damages by phytoceuticals and nutraceuticals

    International Nuclear Information System (INIS)

    Nair, C.K.K.

    2012-01-01

    Exposure of living systems to ionizing radiation cause a variety of damages to DNA and membranes due to generation of free radicals and reactive oxygen species. The radiation induced lesions in the cellular DNA are mainly strand breaks, damage to sugar moiety, alterations and elimination of bases, cross links of the intra and inter strand type and cross links to proteins while peroxidation of the lipids and oxidation of proteins constitute the major lesions in the membranes. The radioprotectors elicit their action by various mechanisms such as i) by suppressing the formation of reactive species, ii) detoxification of radiation induced species, iii) target stabilization and iv) enhancing the repair and recovery processes. The radioprotective compounds are of importance in medical, industrial, environmental, military and space science applications. Radiation protection might offer a tactical advantage on the battlefield in the event of a nuclear warfare. Radioprotectors might reduce the cancer risk to populations exposed to radiations directly or indirectly through industrial and military applications. The antioxidant and radioprotective properties a few of these agents under in vitro and in vivo conditions in animal models will be discussed

  12. Radiation damage studies of detector-compatible Si JFETs

    International Nuclear Information System (INIS)

    Dalla Betta, Gian-Franco; Boscardin, Maurizio; Candelori, Andrea; Pancheri, Lucio; Piemonte, Claudio; Ratti, Lodovico; Zorzi, Nicola

    2007-01-01

    We have largely improved the performance of our detector-compatible Si JFETs by optimizing the fabrication technology. New devices feature thermal noise values close to the theoretical ones, and remarkably low 1/f noise figures. In view of adopting these JFETs for X-ray imaging and HEP applications, bulk and surface radiation damage tests have been carried out by irradiating single transistors and test structures with neutrons and X-rays. Selected results from static and noise characterization of irradiated devices are discussed in this paper, and the impact of radiation effects on the performance of JFET-based circuits is addressed

  13. Radiation damage and induced tetraploidy in mulberry (Morus alba L.)

    International Nuclear Information System (INIS)

    Katagiri, K.

    1976-01-01

    Vigorously growing mulberry shoots were exposed to 5 kR of gamma rays at the rate of 0.2 kR/hr and 5.0 kR/hr and successively pruned three times in two growing seasons. The most radiosensitive part of both the apical and axillary meristems was the second cell layer. The younger axillary bud primordia were more sensitive to radiation then the older ones. Recovery from radiation damage was assumed to be from the flank meristem in the shoot apex. The frequency of mutations was much lower than that of tetraploidy. Among the tetraploids 50% were 2-4-4 chimeras. (author)

  14. Prediction of radiation-related small-bowel damage

    International Nuclear Information System (INIS)

    Potish, R.A.

    1980-01-01

    In order to predict which patients have a high risk for radiation-related small-bowel damage, the concept of the dose-response curve was applied to the predisposing factors (number of previous laparotomies, extent of surgery, thin physique, hypertension, age, cancer stage, number of treatment days, fractionation, and weight change during radiotherapy) present in 92 patients receiving identical radiation doses and volumes This analysis allows an estimate of the probability of complication to be assigned to individual patients. The utility and limitations of the dose-response concept are discussed

  15. Radiation damage assessment of Nb tunnel junction devices

    International Nuclear Information System (INIS)

    King, S.E.; Magno, R.; Maisch, W.G.

    1991-01-01

    This paper reports on the radiation hardness of a new technology using Josephson junctions that was explored by an irradiation using a fluence of 7.6 x 10 14 protons/cm 2 at an energy of 63 MeV from the U.C. Davis cyclotron. In what the authors believe is the first radiation assessment of Nb/Al 2 O 3 /Nb devices, the permanent damage in these devices was investigated. No permanent changes in the I-V characteristics of the junctions were observed indicating no significant level of material defects have occurred at this level of irradiation

  16. Influence of radiation damage on internal friction background

    International Nuclear Information System (INIS)

    Burbelo, R.M.; Grinik, Eh.U.; Paliokha, M.I.; Orlinskij, A.B.

    1984-01-01

    Influence of radiation damage on internal friction background in samples of polycrystalline nickel and iron irradiated by a fast neutron flux approximately 10 14 neutr/(cm 2 xs) at 350 deg C has been studied using the low-frequency unit of the reverse torsion pendulum type. It has been established experimentally that a high-temperature background of internal friction of iron and nickel samples decreases as accumulating radiation defects occurring under neutron irradiation. Assumptions on a possible mechanism of the effect have been proposed. Simple expression for the background magnitude evaluation has been suggested

  17. Cytogenetic techniques for biological indications and dosimetry of of radiation damages in humans

    International Nuclear Information System (INIS)

    Hadjidekova, V.

    2003-01-01

    The cytogenetic methods present a proved way for bio-monitoring and bio-dosimetry for persons, submitted to ionising radiation in occupational and emergency conditions. Their application complement and assist the evaluation of the physical dosimetry and takes in account the individual radiosensitivity of the organism. A comparative assessment is made of the cytogenetic markers for radiation damage of humans applied in Bulgaria. It is discussed the sensitivity of the methods and their development in the last years, as well as the basic concept for their application - the causal relationship between the frequency of the observation of cytogenetic markers in peripheral blood lymphocytes and the risk of oncological disease. The conventional analysis of dicentrics is recognised as a 'golden standard' for the quantitative assessment of the radiation damage. The long term persisting translocations reflect properly the cumulative dose burden from chronic exposure. The micronucleus test allows a quick screening of large groups of persons, working in ionising radiation environment. The combined application with centromeric DNA probe improves the sensitivity and presents a modern alternative of the bio-monitoring and bio-dosimetry. It is discussed the advantages of the different cytogenetic techniques and their optimised application for the assessment of the radiation impact on humans

  18. Radiation damage measurements on CZT drift strip detectors

    DEFF Research Database (Denmark)

    Kuvvetli, Irfan; Budtz-Jørgensen, Carl; Korsbech, Uffe C C

    2003-01-01

    from 2 x 10(8) to 60 x 10(8) p(+)/cm(2). Even for the highest fluences, which had a dramatic effect on the spectroscopic performance, we were able to recover the detectors after an appropriate annealing procedure. The radiation damage was studied as a function of depth inside the detector material...... with the proton dose. The radiation contribution to the electron trapping was found to obey the following relation: (mutau(e)(-1))(rad) = (2.5+/-0.2) x 10(-7) x Phi (V/cm)(2) with the proton fluence, Phi in p(+)/cm(2). The trapping depth dependence, however, did not agree well with the damage profile calculated...

  19. Intensification of ultraviolet-induced dermal damage by infrared radiation

    International Nuclear Information System (INIS)

    Kligman, L.H.

    1982-01-01

    To assess the role of IR in actinic damage to the dermis, albino guinea pigs were irradiated for 45 weeks with UV-B and UV-A, with and without IR. Control animals received IR only or no irradiation at all. Unirradiated dermis contains small amounts of elastic fibers in the upper dermis with greater depositions around follicles and sebaceous glands. After irradiation with UV, the fibers became more numerous, thicker, and more twisted; IR alone producd many fine, feathery fibers. The addition of IR to UV resulted in dense matlike elastic fiber depositions that exceeded what was observed with either irradiation alone. In combination or alone UV and IR radiation produced a large increase in ground substance, a finding also seen in actinically damaged human skin. Infrared radiation, in the physiologic range, though pleasant is not innocuous. (orig./MG) [de

  20. The Global Environment Radiation Monitoring Network (GERMON)

    International Nuclear Information System (INIS)

    Zakheim, B.J.; Goellner, D.A.

    1994-01-01

    Following the Chernobyl accident in 1986, a group of experts from the World Health Organization (WHO) and the United Nations Environment Program (UNEP) met in France to discuss and develop the basic principles of a global environmental radiation monitoring network (GERMON). The basic functions of this network were to provide regular reports on environmental radiation levels and to be in a position to provide reliable and accurate radiation measurements on a quick and accurate radiation measurements on a quick turnaround basis in the event of a major radiation release. By 1992, although 58 countries had indicated an interest in becoming a part of the GERMON system, only 16 were providing data on a regular basis. This paper traces the history of GERMON from its inception in 1987 through its activities during 1993-4. It details the objectives of the network, describes functions, lists its participants, and presents obstacles in the current network. The paper examines the data requirements for radiological emergency preparedness and offers suggestions for the current system. The paper also describes the growing need for such a network. To add a domestic perspective, the authors present a summary of the environmental monitoring information system that was used by the NRC in 1986 in its analyses of the Chernobyl incident. Then we will use this 1986 experience to propose a method for the use of GERMON should a similar occasion arise in the future

  1. Workplace monitoring for radiation and contamination

    International Nuclear Information System (INIS)

    2004-01-01

    Ionizing radiations cannot be seen, felt or sensed by the human body in any way but excessive exposure to them may have adverse health effects. Radiation measuring instruments are needed in order to detect the presence of such radiations and avoid excessive exposure. The use of appropriate and efficient instruments enables exposures to be controlled and the doses received to be kept as low as reasonably achievable. This Manual explains the basic terminology associated with such measuring instruments and describes the principal types, their construction and typical applications in the workplace. It is important to ensure not only that monitoring is carried out where there is a potential radiation exposure but also that the monitoring instrument is appropriate to the task and that the user places correct interpretations on the results obtained. The Manual will be of most benefit if it forms part of more comprehensive training or is supplemented by the advice of a qualified expert in radiation protection. Some of the instrument tests and calibrations described in this Manual require the services of a qualified expert

  2. Mexamine used to decrease radiation damage to Wistar rat embryogenesis

    International Nuclear Information System (INIS)

    Palyga, G.F.; Zakoshchikov, K.F.

    1987-01-01

    In experiments with 330 Wistar rats experiencing their pregnancy and 1430 neonatal rats of the first generation a study was made on the toxicity and radioprotective efficiency of a single subcutaneous injection of 10 mg/kg mexamine on days 3, 11 and 19 pregnancy. The agent caused various abnormalities in pregnancy, delivery and postnatal development of the offspring of nonirradiated animals, and it was almost ineffective when used for the prevention of radiation damages during the anrnatal ontogenesis

  3. Effect of radiation damage on the infrared properties of apatite

    International Nuclear Information System (INIS)

    Anis Faridah Md Nori; Yusof Mohd Amin; Rosli Mahat; Burhanuddin Kamaluddin

    1991-01-01

    Apatites are known to contain radioactive elements such as uranium and thorium at a few ppm in concentration. These elements decay and produce fission tracks inside the crystals. The presence of such tracks have been known to affect the thermoluminescence (TL) properties of apatites. These fission tracks can be removed by annealing the crystals in air. In this paper we present the result of a preliminary study on the effect of radiation damage on the infrared transmission of apatites

  4. Reduction in thermal conductivity of ceramics due to radiation damage

    International Nuclear Information System (INIS)

    Klemens, P.G.; Hurley, G.F.; Clinard, F.W. Jr.

    1976-01-01

    Ceramics are required for a number of applications in fusion reactors. In several of these applications, the thermal conductivity is an important design parameter as it affects the level of temperature and thermal stress in service. Ceramic insulators are known to suffer substantial reduction in thermal conductivity due to neutron irradiation damage. The present study estimates the reduction in thermal conductivity at high temperature due to radiation induced defects. Point, extended, and extended partly transparent defects are considered

  5. Radiation damage status of the ATLAS silicon strip detectors (SCT)

    CERN Document Server

    Kondo, Takahiko; The ATLAS collaboration

    2017-01-01

    The Silicon microstrip detector system (SCT) of the ATLAS experiment at LHC has been working well for about 7 years since 2010. The innermost layer has already received a few times of 10**13 1-MeV neutron-equivalent fluences/cm2. The evolutions of the radiation damage effects on strip sensors such as leakage current and full depletion voltages will be presented.

  6. Ascorbic acid (AA) metabolism in protection against radiation damage

    International Nuclear Information System (INIS)

    Rose, R.C.; Koch, M.J.

    1986-01-01

    The possibility is considered that AA protects tissues against radiation damage by scavenging free radicals that result from radiolysis of water. A physiologic buffer (pH 6.7) was incubated with 14 C-AA and 1 mM thiourea (to slow spontaneous oxidation of AA). Aliquots were assayed by HPLC and scintillation spectrometry to identify the 14 C-label. Samples exposed to Cobalt-60 radiation had a half time of AA decay of 30 minutes) indicating that AA scavenges radiation-induced free radicals and forms the ascorbate free radical (AFR). Pairs of 14 C-AFR disproportionate, with the net effect of 14 C-dehydroascorbic acid formation from 14 C-AA. Having established that AFR result from ionizing radiation in an aqueous solution, the possibility was evaluated that a tissue factor reduces AFR. Cortical tissue from the kidneys of male rats was minced, homogenized in buffer and centrifuged at 8000 xg. The supernatant was found to slow the rate of radiation-induced AA degradation by > 90% when incubated at 23 0 C in the presence of 15 μM 14 C-AA. Samples of supernatant maintained at 100 0 C for 10 minutes or precipitated with 5% PCA did not prevent radiation-induced AA degradation. AA may have a specific role in scavenging free radicals generated by ionizing radiation and thereby protect body tissues

  7. Historical update of past and recent skin damage radiation accidents

    International Nuclear Information System (INIS)

    Lushbaugh, C.C.; Fry, S.A.; Ricks, R.C.; Hubner, K.F.; Burr, W.W.

    1986-01-01

    Records of radiation accidents worldwide since 1944 are maintained at the Radiation Accident Registry of the Radiation Emergency Assistance Center/Training Site (REAC/TS) in Oak Ridge. These records show that in 263 major radiation accidents there have been 150 severe local radiation injuries, of which 117 have been exposure to sealed radioactive sources. Most lesions resulted from the unsafe handling of 192 Ir radiography sources. Recent redesign of these devices, used for testing the integrity of welds, promises to eliminate these accidents. However, many other kinds of irradiators used in industry and scientific research still remain in the public domain, capable of causing irreparable dermal damage. Registry records reveal many unsolved physical and medical problems whose solution is urgently needed to improve the prognosis and therapy of such lesions. Pathologically, radiation-induced skin lesions are well described and an approximate dose-response relationship is univerally accepted even though the actual 'dose' is rarely known at first. Radiation dose is estimated biologically after the lesion has run its pathological course or after a medical physicist has prepared a retrospective 'mock-up' of the accident. (author)

  8. Radiobiology in clinical radiation therapy - Part III: Normal tissue damage

    International Nuclear Information System (INIS)

    Travis, Elizabeth L.

    1996-01-01

    Objective: This is the third part of a course designed for residents in radiation oncology preparing for their boards. This part of the course will focus on the mechanisms underlying damage in normal tissues. Although conventional wisdom long held that killing and depletion of a critical cell(s) in a tissue was responsible for the later expression of damage, histopathologic changes in normal tissue can now be explained and better understood in terms of the new molecular biology. The concept that depletion of a single cell type is responsible for the observed histopathologic changes in normal tissues has been replaced by the hypothesis that damage results from the interaction of many different cell systems, including epithelial, endothelial, macrophages and fibroblasts, via the production of specific autocrine, paracrine and endocrine growth factors. A portion of this course will discuss the clinical and experimental data on the production and interaction of those cytokines and cell systems considered to be critical to tissue damage. It had long been suggested that interindividual differences in radiation-induced normal tissue damage was genetically regulated, at least in part. Both clinical and experimental data supported this hypothesis but it is the recent advances in human and mouse molecular genetics which have provided the tools to dissect out the genetic component of normal tissue damage. These data will be presented and related to the potential to develop genetic markers to identify sensitive individuals. The impact on clinical outcome of the ability to identify prospectively sensitive patients will be discussed. Clinically it is well-accepted that the volume of tissue irradiated is a critical factor in determining tissue damage. A profusion of mathematical models for estimating dose-volume relationships in a number of organs have been published recently despite the fact that little data are available to support these models. This course will review the

  9. Gamma radiation damage in pixelated detector based on carbon nanotubes

    International Nuclear Information System (INIS)

    Leyva, A.; Pinnera, I.; Leyva, D.; Abreu, Y.; Cruz, C. M.

    2013-01-01

    The aim of this paper is to evaluate the possible gamma radiation damage in high pixelated based on multi-walled carbon nanotubes detectors, grown on two different substrata, when it is operating in aggressive radiational environments. The radiation damage in displacements per atom (dpa) terms were calculated using the MCCM algorithm, which takes into account the McKinley-Feshbach approach with the Kinchin-Pease approximation for the damage function. Was observed that with increasing of the gamma energy the displacement total number grows monotonically reaching values of 0.39 displacements for a 10 MeV incident photon. The profiles of point defects distributions inside the carbon nanotube pixel linearly rise with depth, increasing its slope with photon energy. In the 0.1 MeV - 10 MeV studied energy interval the electron contribution to the total displacement number become higher than the positron ones, reaching this last one a maximum value of 12% for the 10 MeV incident photons. Differences between the calculation results for the two used different substrata were not observed. (Author)

  10. Low dose radiation damage effects in silicon strip detectors

    International Nuclear Information System (INIS)

    Wiącek, P.; Dąbrowski, W.

    2016-01-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  11. Low dose radiation damage effects in silicon strip detectors

    Science.gov (United States)

    Wiącek, P.; Dąbrowski, W.

    2016-11-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  12. Determination of radiation direction in environmental monitoring

    International Nuclear Information System (INIS)

    Campos, Vicente de Paulo de; Moura, Eduardo S.; Rocha, Felicia D.G.; Manzoli, Jose Eduardo

    2009-01-01

    The assessment of environmental exposure has been performed in Brazil using the thermoluminescence technique at Thermoluminescence Dosimetry Laboratory (LDT), at Nuclear and Energetic Research Institute (IPEN/CNEN-SP). To carry out these measurements, several thermoluminescent dosimeters (TLD's) were used to measure the expose. In this procedure, very few information of direction where the radiation came from is available. A vague supposition about the direction from where the radiation came from could be inferred only by evaluation of multiple dosimeters displaced at entire region of monitoring, but this demand to much effort or sometimes become impractical for certain situations. In this work, a single device is used to provide information about the direction from where the radiation came through. This device is called directional dosimeter (DD). Using more than one DD it is possible to reduce the uncertainty of the measurements and determine the radiation source position. The DD basically consists of a regular solid with high effective atomic number, where one TLD is positioned at each face. The DD allows evaluating the environmental exposure and the direction of the radiation by a simple vector sum. At each face of the DD, it is associated an orthogonal vector, and modulus of this vector represents the correspond exposure measured by the TLD. The direction of the radiation source is the sum of these faces vectors. The prototype used in this work was a lead cube with six TLDs of CaSO 4 :Dy/Teflon. The TLDs have high sensibility and are already used in area, environmental and personal monitoring. The measurements had shown the correct environmental exposure and a good indication of the radiation direction. (author)

  13. First Results from the Online Radiation Dose Monitoring System in ATLAS experiment

    CERN Document Server

    Mandić, I; The ATLAS collaboration; Deliyergiyev, M; Gorišek, A; Kramberger, G; Mikuž, M; Franz, S; Hartert, J; Dawson, I; Miyagawa, P S; Nicolas, L

    2011-01-01

    High radiation doses which will accumulate in components of ATLAS experiment during data taking will cause damage to detectors and readout electronics. It is therefore important to continuously monitor the doses to estimate the level of degradation caused by radiation. Online radiation monitoring system measures ionizing dose in SiO2 and fluences of 1-MeV(Si) equivalent neutrons and thermal neutrons at several locations in ATLAS detector. In this paper measurements collected during two years of ATLAS data taking are presented and compared to predictions from radiation background simulations.

  14. Study on radiation damage of electron and γ-rays and mechanism of nuclear hardening

    International Nuclear Information System (INIS)

    Jing Tao

    2001-01-01

    Radiation damage effects of electrons and γ-rays are presented. The damage defects are studied by experimental methods. On the basis of these studies the damage mechanism and nuclear hardening techniques are studied

  15. Acetylation dynamics of human nuclear proteins during the ionizing radiation-induced DNA damage response

    DEFF Research Database (Denmark)

    Bennetzen, Martin; Andersen, J.S.; Lasen, D.H.

    2013-01-01

    Genotoxic insults, such as ionizing radiation (IR), cause DNA damage that evokes a multifaceted cellular DNA damage response (DDR). DNA damage signaling events that control protein activity, subcellular localization, DNA binding, protein-protein interactions, etc. rely heavily on time...

  16. Environmental radiation monitoring in Sao Paulo state

    International Nuclear Information System (INIS)

    Agudo, E.G.; Albuquerque, A.M. de; Vasconcellos, N.V. de

    1991-01-01

    The results of environmental radiation monitoring that CETESB (Technological Company of Environmental Sanitation of Sao Paulo) does in influence areas of radioactive materials store of Nuclemon Minero-Quimica S.A. in the municipality of Itu, Sao Paulo State, are presented. The data comprises the period of 1983-1990 with information about concentration levels of radium-225 in underground and superficial waters of the region. On March, 1989, was detected contamination in a well near of the stores. The levels observed, its implications in terms of health risks and possible causes of event are discussed too. The goals that CETESB intends to reach in terms of monitoring of environmental radiation in Sao Paulo State are also presented. (C.M.)

  17. Autonomous radiation monitoring of small vessels

    International Nuclear Information System (INIS)

    Ziock, K.P.; Cheriyadat, A.; Fabris, L.; Goddard, J.; Hornback, D.; Karnowski, T.; Kerekes, R.; Newby, J.

    2011-01-01

    Small private vessels are one avenue by which nuclear materials may be smuggled across international borders. While one can contemplate using the land-based approach of radiation portal monitors on the navigable waterways that lead to many ports, these systems are ill-suited to the problem. In contrast to roadways, where lanes segregate vehicles, and motion is well controlled by inspection booths; channels, inlets, and rivers present chaotic traffic patterns populated by vessels of all sizes. A unique solution to this problem is based on a portal-less portal monitor designed to handle free-flowing traffic on roadways with up to five-traffic lanes. The instrument uses a combination of visible-light and gamma-ray imaging to acquire and link radiation images to individual vehicles. This paper presents the results of a recent test of the system in a maritime setting.

  18. GERMON. Global Environmental Radiation Monitoring Network

    International Nuclear Information System (INIS)

    1992-01-01

    Between 15-18 December 1987, a meeting of experts of WHO/UNEP met at Le Vesinet, France, to develop the basic principles of a global environmental radiation monitoring network (GERMON) which would have the function of reporting on a regular basis environmental radiation levels, and be positioned to provide rapid and reliable radiation measurements in the event of a major radiation release. To date, some 58 countries have indicated their willingness to become part of GERMON. About 40 of these have technical staff and equipment to meet the minimum requirements for joining the network, and about 30 have designated appropriate organizations within their country to serve as national Liaison Institutions for GERMON. Sixteen countries are now providing data on a regular basis to the CCC at SCPRI in Le Vesinet, France. Thirty-two countries responded to the request of WHO for readiness to take part in a IAEA radiation emergency exercise. The present meeting has been held in Montgomery, Alabama, USA at the National Air and Radiation Environmental Laboratory between 27 April 1992 and 30 April 1992, with the purpose of reviewing GERMON. One important topic considered was the implementation of GERMON in the Americas. Particular attention was given to the need for better coordination with IAEA in responding to the Convention on Early Notification, to the role of the CCC, to forms of data transmission, etc

  19. Radiation damage of DNA. Model for direct ionization of DNA

    International Nuclear Information System (INIS)

    Kobayashi, Kazuo; Tagawa, Seiichi

    2004-01-01

    Current aspects of radiation damage of DNA, particularly induced by the direct effect of radiation, and author's method of pulse radiolysis are described in relation to behavior of ions formed by radiation and active principles to induce the strand break. In irradiation of DNA solution in water, the direct effect of radiation is derived from ionization of DNA itself and indirect one, from the reaction between DNA and radicals generated from water molecules and the former direct one has been scarcely investigated due to difficulty of experimental approach. Radicals generated in sugar moiety of DNA are shown important in the strand break by recent studies on crystalline DNA irradiated by X-ray, DNA solution by electron and photon beams, hydrated DNA by γ-ray and by high linear energy transfer (LET) ion. Author's pulse radiolysis studies have revealed behaviors of guanine and adenine radical cations in dynamics of DNA oxidation. Since reactions described are the model, the experimental approach is thought necessary for elucidation of the actually occurring DNA damage in living cells. (N.I.)

  20. Investigation of damage mechanism by ionising radiation on biomolecules

    International Nuclear Information System (INIS)

    Lau How Mooi

    1996-01-01

    Occupational radiation hazard is a very controversial subject. Effects from high radiation doses are well known from past experiences. However, hazard from low doses is still a subject that is hotly debated upon until now. The occupational dosimetry used now is based on a macroscopic scale. Lately, microdosimetry is fast gaining recognition as a more superior way of measuring hazard. More importantly, scientists are researching the basic damage mechanism that leads to biological effects by ionising radiation. In this report, a simulation study of the basic damage mechanism is discussed . This simulation is based upon Monte Carlo calculations and using polyuridylic acid (Poly-U) as the DNA model This simulation tries to relate the physics and chemistry of interactions of ionising radiation with biomolecules. The computer codes used in this simulation, OREC and RADLYS were created by Hamm et al. (1983) in Oak Ridge National Laboratory. The biological endpoints in this simulation are the strand break and base release of the DNA, which is the precursor of all biological effects. These results are compared with model studies that had been done experimentally to check the validity of this simulation. The G-values of strand break and base release from this simulation were -2.35 and 2.75 and compared well with results from irradiation experiments by von Sonntag (I 98 7) from Max Plank's Institute, Germany

  1. Experimental studies on radiation damages of CsI(Tl) crystals

    International Nuclear Information System (INIS)

    He Jingtang; Mao Yufang; Dong Xiaoli; Chen Duanbao; Li Zuhao

    1997-01-01

    The results of experimental studies on radiation damage of CsI(Tl) crystal were reported. There are radiation damage effects on CsI(Tl) crystal. Experimental studies on recovery of damaged CsI(Tl) crystals were made. It seems that after heating at 200 degree C for 4 hours, the damaged crystals could be recovered completely

  2. Chromatin modifications and the DNA damage response to ionizing radiation

    International Nuclear Information System (INIS)

    Kumar, Rakesh; Horikoshi, Nobuo; Singh, Mayank; Gupta, Arun; Misra, Hari S.; Albuquerque, Kevin; Hunt, Clayton R.; Pandita, Tej K.

    2013-01-01

    In order to survive, cells have evolved highly effective repair mechanisms to deal with the potentially lethal DNA damage produced by exposure to endogenous as well as exogenous agents. Ionizing radiation exposure induces highly lethal DNA damage, especially DNA double-strand breaks (DSBs), that is sensed by the cellular machinery and then subsequently repaired by either of two different DSB repair mechanisms: (1) non-homologous end joining, which re-ligates the broken ends of the DNA and (2) homologous recombination, that employs an undamaged identical DNA sequence as a template, to maintain the fidelity of DNA repair. Repair of DSBs must occur within the natural context of the cellular DNA which, along with specific proteins, is organized to form chromatin, the overall structure of which can impede DNA damage site access by repair proteins. The chromatin complex is a dynamic structure and is known to change as required for ongoing cellular processes such as gene transcription or DNA replication. Similarly, during the process of DNA damage sensing and repair, chromatin needs to undergo several changes in order to facilitate accessibility of the repair machinery. Cells utilize several factors to modify the chromatin in order to locally open up the structure to reveal the underlying DNA sequence but post-translational modification of the histone components is one of the primary mechanisms. In this review, we will summarize chromatin modifications by the respective chromatin modifying factors that occur during the DNA damage response.

  3. Radiation-induced neuropathies: collateral damage of improved cancer prognosis

    International Nuclear Information System (INIS)

    Pradat, Pierre-Francois; Maisonobe, Thierry; Psimaras, Dimitri; Lenglet, Timothee; Porcher, Raphael; Lefaix, J.L.; Delenian, S.

    2012-01-01

    Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system. Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation. The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and

  4. Radiation monitoring network of the Czech Republic

    International Nuclear Information System (INIS)

    Kuca, P.; Novak, L.; Rulik, P.; Tecl, J.

    2003-01-01

    The Radiation Monitoring Network (RMN) of the Czech Republic was established after the Chernobyl accident in 1986 and it is developed all the time. It is co-ordinated by the State Office for Nuclear Safety in co-operation with the National Radiation Protection Institute. Czech RMN consists of the several sub-networks, which include selected or all permanent parts of RMN. The sub-networks are following: the Early Warning Network (EWN), the TLD Territorial Network, the Network of the Measuring Sites of Air Contamination, the Network of Laboratories Equipped with Gamma-spectrometric and Radiochemical Analytical Instrumentation, the Ground and Airborne Mobile Groups. The Laboratory of Monitoring of Internal Contamination and the information system (IS) are a significant part of RMN, too. The data of RMN resulting from monitoring are transferred to the central database of CRMN, processed by the information system (IS). They are used in normal and emergency situations for an evaluation of radiation situation and for preparation of recommendations for protection of the public and the environment. In 2002 any extraordinary radioactivity in the environment was not detected and also none of the measuring points recorded any exceeding of established investigation levels. In components of environment and also in human beings a very low activity of 137 Cs was still measurable, that had been released into environment after the Chernobyl accident and by the nuclear weapon tests in sixties of the last century. (authors)

  5. Radiation damage and rate limitations in tracking devices

    International Nuclear Information System (INIS)

    Gilchriese, M.G.D.

    1984-01-01

    In this note the author briefly discusses radiation damage to wire chambers and silicon strip devices and the electronics that may be associated with each of these. Scintillating fibers and CCD's are not discussed although the former appears to be a potentially radiation-resistant detector. In order to calculate radiation levels and rates the author assumed the following: an inelastic cross section of 100 mb at the SSC - six charged particles per unit of rapidity - photons and neutrons do not contribute to the background (photon conversions are negligible with a thin Be beam pipe) - beam gas interactions and beam losses (except during injection when I assume that the detector is ''off'') are negligible. This is discussed in a later section. - 1 Rad = 3.5 x 10 7 minimum ionizing particlescm 2

  6. Basic aspects of spallation radiation damage to materials

    Energy Technology Data Exchange (ETDEWEB)

    Wechsler, M.S.; Lin, C. [North Carolina State Univ., Raleigh, NC (United States); Sommer, W.F. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    The nature of radiation effects, as learned from investigations using reactor neutron irradiations, is reviewed, and its relevance to spallation radiation damage to materials in accelerator-driven neutron sources is discussed. Property changes upon irradiation are due to (1) displaced atoms, producing vacancy and interstitial defect clusters, which cause radiation hardening and embrittlement; (2) helium production, the helium then forming bubbles, which engenders high-temperature grain-boundary fracture; and (3) transmutations, which means that impurity concentrations are introduced. Methods for analyzing displacement production are related, and recent calculations of displacement cross sections using SPECTER and LAHET are described, with special reference to tungsten, a major candidate for a target material in accelerator-driven neutron systems.

  7. Real Time Radiation Monitoring Using Nanotechnology

    Science.gov (United States)

    Li, Jing (Inventor); Hanratty, James J. (Inventor); Wilkins, Richard T. (Inventor); Lu, Yijiang (Inventor)

    2016-01-01

    System and method for monitoring receipt and estimating flux value, in real time, of incident radiation, using two or more nanostructures (NSs) and associated terminals to provide closed electrical paths and to measure one or more electrical property change values .DELTA.EPV, associated with irradiated NSs, during a sequence of irradiation time intervals. Effects of irradiation, without healing and with healing, of the NSs, are separately modeled for first order and second order healing. Change values.DELTA.EPV are related to flux, to cumulative dose received by NSs, and to radiation and healing effectivity parameters and/or.mu., associated with the NS material and to the flux. Flux and/or dose are estimated in real time, based on EPV change values, using measured .DELTA.EPV values. Threshold dose for specified changes of biological origin (usually undesired) can be estimated. Effects of time-dependent radiation flux are analyzed in pre-healing and healing regimes.

  8. PREFACE: Radiation Damage in Biomolecular Systems (RADAM07)

    Science.gov (United States)

    McGuigan, Kevin G.

    2008-03-01

    The annual meeting of the COST P9 Action `Radiation damage in biomolecular systems' took place from 19-22 June 2007 in the Royal College of Surgeons in Ireland, in Dublin. The conference was structured into 5 Working Group sessions: Electrons and biomolecular interactions Ions and biomolecular interactions Radiation in physiological environments Theoretical developments for radiation damage Track structure in cells Each of the five working groups presented two sessions of invited talks. Professor Ron Chesser of Texas Tech University, USA gave a riveting plenary talk on `Mechanisms of Adaptive Radiation Responses in Mammals at Chernobyl' and the implications his work has on the Linear-No Threshold model of radiation damage. In addition, this was the first RADAM meeting to take place after the Alexander Litvenenko affair and we were fortunate to have one of the leading scientists involved in the European response Professor Herwig Paretzke of GSF-Institut für Strahlenschutz, Neuherberg, Germany, available to speak. The remaining contributions were presented in the poster session. A total of 72 scientific contributions (32 oral, 40 poster), presented by 97 participants from 22 different countries, gave an overview on the current progress in the 5 different subfields. A 1-day pre-conference `Early Researcher Tutorial Workshop' on the same topic kicked off on 19 June attended by more than 40 postgrads, postdocs and senior researchers. Twenty papers, based on these reports, are included in this volume of Journal of Physics: Conference Series. All the contributions in this volume were fully refereed, and they represent a sample of the courses, invited talks and contributed talks presented during RADAM07. The interdisciplinary RADAM07 conference brought together researchers from a variety of different fields with a common interest in biomolecular radiation damage. This is reflected by the disparate backgrounds of the authors of the papers presented in these proceedings

  9. Autonomous Radiation Monitoring of Small Vessels

    International Nuclear Information System (INIS)

    Fabris, Lorenzo; Hornback, Donald Eric

    2010-01-01

    Small private vessels are one avenue by which nuclear materials may be smuggled across international borders. While one can contemplate using the terrestrial approach of radiation portal monitors on the navigable waterways that lead to many ports, these systems are ill-suited to the problem. They require vehicles to pass at slow speeds between two closely-spaced radiation sensors, relying on the uniformity of vehicle sizes to space the detectors, and on proximity to link an individual vehicle to its radiation signature. In contrast to roadways where lanes segregate vehicles, and motion is well controlled by inspection booths; channels, inlets, and rivers present chaotic traffic patterns populated by vessels of all sizes. We have developed a unique solution to this problem based on our portal-less portal monitor instrument that is designed to handle free-flowing traffic on roadways with up to five-traffic lanes. The instrument uses a combination of visible-light and gamma-ray imaging to acquire and link radiation images to individual vehicles. It was recently tested in a maritime setting. In this paper we present the instrument, how it functions, and the results of the recent tests.

  10. Analysis of food radiation monitoring system in Belarus

    International Nuclear Information System (INIS)

    1992-01-01

    Food radiation monitoring system in Belarus due to the Chernobyl accident is analysed. Structure of radiation monitoring network, instrumentation and modern developments. Information on permissible concentration levels in foodstuffs and water is presented and calculations of radionuclide intake for man are performed. Proposals on the creation of social centres of food radiation monitoring for Belarussian population are considered. 4 tabs

  11. Delayed damage after radiation therapy for head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yoshiyuki [Osaka Dental Univ., Hirakata (Japan)

    2000-03-01

    I investigated radiation damage, including osteoradionecrosis, arising from tooth extraction in fields that had received radiation therapy for head and neck cancer, and evaluated the effectiveness of pilocarpine for xerostomia. Between January 1990 and April 1996, I examined 30 patients for bone changes after tooth extraction in fields irradiated at the Department of Oral Radiology, Osaka Dental University Hospital. Nineteen of the patients had been treated for nasopharyngeal cancer and 11 for oropharyngeal cancer. Between January and April 1996, 4 additional patients were given pilocarpine hydrochloride (3-mg, 6-mg and 9-mg of KSS-694 orally three times a day) for 12 weeks and evaluated every 4 weeks as a base line. One had been treated for nasopharyngeal carcinoma, two for cancer of the cheek and one for an unknown carcinoma. Eighteen of the patients (11 with nasopharyngeal carcinoma and 7 with oropharyngeal carcinoma) had extractions. Use of preoperative and postoperative radiographs indicated that damage to the bone following tooth extraction after radiation exposure was related to whether antibiotics were administered the day before the extraction, whether forceps or elevators were used, and whether the tooth was in the field of radiation. Xerostomia improved in all 4 of the patients who received 6-mg or 9-mg of pilocarpine. It improved saliva production and relieved the symptoms of xerostomia after radiation therapy for head and neck cancer, although there were minor side effects such as fever. This information can be used to improve the oral environment of patients who have received radiation therapy for head and neck cancer, and to better understand their oral environment. (author)

  12. Delayed damage after radiation therapy for head and neck cancer

    International Nuclear Information System (INIS)

    Matsumoto, Yoshiyuki

    2000-01-01

    I investigated radiation damage, including osteoradionecrosis, arising from tooth extraction in fields that had received radiation therapy for head and neck cancer, and evaluated the effectiveness of pilocarpine for xerostomia. Between January 1990 and April 1996, I examined 30 patients for bone changes after tooth extraction in fields irradiated at the Department of Oral Radiology, Osaka Dental University Hospital. Nineteen of the patients had been treated for nasopharyngeal cancer and 11 for oropharyngeal cancer. Between January and April 1996, 4 additional patients were given pilocarpine hydrochloride (3-mg, 6-mg and 9-mg of KSS-694 orally three times a day) for 12 weeks and evaluated every 4 weeks as a base line. One had been treated for nasopharyngeal carcinoma, two for cancer of the cheek and one for an unknown carcinoma. Eighteen of the patients (11 with nasopharyngeal carcinoma and 7 with oropharyngeal carcinoma) had extractions. Use of preoperative and postoperative radiographs indicated that damage to the bone following tooth extraction after radiation exposure was related to whether antibiotics were administered the day before the extraction, whether forceps or elevators were used, and whether the tooth was in the field of radiation. Xerostomia improved in all 4 of the patients who received 6-mg or 9-mg of pilocarpine. It improved saliva production and relieved the symptoms of xerostomia after radiation therapy for head and neck cancer, although there were minor side effects such as fever. This information can be used to improve the oral environment of patients who have received radiation therapy for head and neck cancer, and to better understand their oral environment. (author)

  13. Contribution of endogenous and exogenous damage to the total radiation-induced damage in the bacterial spore

    International Nuclear Information System (INIS)

    Jacobs, G.P.; Samuni, A.; Czapski, G.

    1980-01-01

    Radical scavengers such as polyethylene glycol 4000 and bovine albumin have been used to define the contribution of exogenous and endogenous damage to the total radiation-induced damage in aqueous buffered suspensions of Bacillus pumilus spores. The results indicate that this damage in the bacterial spore is predominantly endogenous

  14. Environmental radiation monitoring technology: Capabilities and needs

    International Nuclear Information System (INIS)

    Hofstetter, K.J.

    1994-01-01

    Radiation monitoring in the Savannah River Site (SRS) environment is conducted by a combination of automated, remote sampling and/or analysis systems, and manual sampling operations. This program provides early detection of radionuclide releases, minimizes the consequences, and assesses the impact on the public. Instrumentation installed at the release points monitor the atmospheric and aqueous releases from SRS operations. Ground water and air monitoring stations are strategically located throughout the site for radionuclide migration studies. The environmental radiological monitoring program at SRS includes: fixed monitoring stations for atmospheric radionuclide concentrations, aqueous monitors for surface water measurements, mobile laboratory operations for real-time, in-field measurements, aerial scanning for wide area contamination surveillance, and hand-held instruments for radionuclide-specific measurements. Rigorous environmentnal sampling surveillance coupled with laboratory analyses provide confirmatory results for all in-field measurements. Gaps in the technologies and development projects at SRS to fill these deficiencies are discussed in the context of customer needs and regulatory requirements

  15. Heavy ion linear accelerator for radiation damage studies of materials

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey V.; Mustapha, Brahim; Ostroumov, Peter N.; Nolen, Jerry; Barcikowski, Albert; Pellin, Michael; Yacout, Abdellatif

    2017-03-01

    A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for U-238(50+) and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

  16. Heavy ion linear accelerator for radiation damage studies of materials.

    Science.gov (United States)

    Kutsaev, Sergey V; Mustapha, Brahim; Ostroumov, Peter N; Nolen, Jerry; Barcikowski, Albert; Pellin, Michael; Yacout, Abdellatif

    2017-03-01

    A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for 238 U 50+ and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

  17. Curcumin Attenuates Gamma Radiation Induced Intestinal Damage in Rats

    International Nuclear Information System (INIS)

    EI-Tahawy, N.A.

    2009-01-01

    Small Intestine exhibits numerous morphological and functional alterations during radiation exposure. Oxidative stress, a factor implicated in the intestinal injury may contribute towards some of these alterations. The present work was designed to evaluate the efficacy of curcumin, a yellow pigment of turmeric on y-radiation-induced oxidative damage in the small intestine by measuring alterations in the level of thiobarbituric acid reactive substances (TSARS), serotonin metabolism, catecholamine levels, and monoamine oxidase (MAO) activity in parallel to changes in the architecture of intestinal tissues. In addition, monoamine level, MAO activity and TSARS level were determined in the serum. Curcumin was supplemented orally via gavages, to rats at a dose of (45 mg/ Kg body wt/ day) for 2 weeks pre-irradiation and the last supplementation was 30 min pre exposure to 6.5 Gy gamma radiations (applied as one shot dose). Animals were sacrificed on the 7th day after irradiation. The results demonstrated that, whole body exposure of rats to ionizing radiation has induced oxidative damage in small intestine obvious by significant increases of TSARS content, MAO activity and 5-hydroxy indole acetic acid (5-HIAA) and by significant decreases of serotonin (5-HT), dopamine (DA), norepinephrine (NE) and epinephrine (EPI) levels. In parallel histopathological studies of the small intestine of irradiated rats through light microscopic showed significant decrease in the number of villi, villus height, mixed sub mucosa layer with more fibres and fibroblasts. Intestinal damage was in parallel to significant alterations of serum MAO activity, TBARS, 5-HT, DA, NE and EPI levels. Administration of curcumin before irradiation has significantly improved the levels of monoamines in small intestine and serum of irradiated rats, which was associated with significant amelioration in MAO activity and TBARS contents

  18. Defense mechanisms against radiation induced teratogenic damage in mice

    International Nuclear Information System (INIS)

    Kato, F.; Ootsuyama, A.; Nomoto, S.; Norimura, T.

    2002-01-01

    Experimental studies with mice have established that fetuses at midgestational stage are highly susceptible to malformation at high, but not low, doses of radiation. When DNA damage is produced by a small amount of radiation, it is efficiently eliminated by DNA repair. However, DNA repair is not perfect. There must be defense mechanisms other than DNA repair. In order to elucidate the essential role of p53 gene in apoptotic tissue repair, we compared the incidence of radiation-induced malformations and deaths (deaths after day 10) in wild-type p53 (+/+) mice and null p53 (-/-) mice. For p53 (+/+) mice, an X-ray dose of 2 Gy given at a high dose-rate (450 mGy/min) to fetuses at 9.5 days of gestation was highly lethal and considerably teratogenic whereas it was only slightly lethal but highly teratogenic for p53 (-/-) fetuses. This reciprocal relationship of radiosensitivity to malformations and deaths supports the notion that fetal tissues have a p53 -dependent idguardianln of the tissue that aborts cells bearing radiation-induced teratogenic DNA damage. When an equal dose of 2 Gy given at a 400-fold lower dose-rate (1.2 mGy/min), this dose became not teratogenic for p53 (+/+) fetuses exhibiting p53 -dependent apoptosis, whereas this dose remained teratogenic for p53 (-/-) fetuses unable to carry out apoptosis. Furthermore, when the dose was divided into two equal dose fractions (1+1 Gy) at high dose rate, separated by 24 hours, the incidences of malformations were equal with control level for p53 (+/+), but higher for p53 (-/-) mice. Hence, complete elimination of teratogenic damage from irradiated tissues requires a concerted cooperation of two mechanisms; proficient DNA repair and p53-dependent apoptotic tissue repair

  19. Airborne radiation monitoring using a manned helicopter

    International Nuclear Information System (INIS)

    Sanada, Yukihisa; Nishizawa, Yukiyasu; Ishizaki, Azusa; Urabe, Yoshimi

    2017-01-01

    The Great East Japan Earthquake that occurred on 11 March 2011 generated a series of large tsunami waves that caused serious damage to the Fukushima Dai-ichi Nuclear Power Station, following which a large amount of radioactive material was discharged from the nuclear power plant into the environment. Airborne radiation measurements using a manned helicopter were applied to measure the radiation distribution immediately after accident as technique to quickly measure the radiation distribution over a wide area. In Japan, this technique was researched and developed in the 1980s. However, this technique and system were not applied immediately after the accident because standardization of analysis was not established and the Japanese system became deteriorated. This technique is important for post-accident studies at a nuclear facility. We summarized the methods of the airborne radiation measurement using a manned helicopter. In addition, measurement results of the dose rate distribution at the Fukushima Dai-ichi Nuclear Power Station are given in this paper. (author)

  20. A radiation monitoring system for nuclear power plants

    International Nuclear Information System (INIS)

    Iwai, Masaru; Nakamori, S.; Ikeda, H.; Oda, M.

    1974-01-01

    Safety with respect to radiation is vital factor, particularly in view of the increasing number of nuclear power plants. For this purpose, a radiation monitoring system is provided to perform constant supervision. This article describes the purpose, installation location, specifications and circuitry of a system which is divided into three units: the process monitor, area monitor and off-site monitor. (auth.)

  1. Protective Effect of HSP25 on Radiation Induced Tissue Damage

    International Nuclear Information System (INIS)

    Lee, Hae-June; Lee, Yoon-Jin; Kwon, Hee-Choong; Bae, Sang-Woo; Lee, Yun-Sil; Kim, Sung Ho

    2007-01-01

    Control of cancer by irradiation therapy alone or in conjunction with combination chemotherapy is often limited by organ specific toxicity. Ionizing irradiation toxicity is initiated by damage to normal tissue near the tumor target and within the transit volume of radiotherapy beams. Irradiation-induced cellular, tissue, and organ damage is mediated by acute effects, which can be dose limiting. A latent period follows recovery from the acute reaction, then chronic irradiation fibrosis (late effects) pose a second cause of organ failure. HSP25/27 has been suggested to protect cells against apoptotic cell death triggered by hyperthermia, ionizing radiation, oxidative stress, Fas ligand, and cytotoxic drugs. And several mechanisms have been proposed to account for HSP27-mediated apoptotic protection. However radioprotective effect of HSP25/27 in vivo system has not yet been evaluated. The aim of this study was to evaluate the potential of exogenous HSP25 expression, as delivered by adenoviral vectors, to protect animal from radiation induced tissue damage

  2. Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

    CERN Document Server

    Ducourthial, Audrey; The ATLAS collaboration

    2017-01-01

    Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of $10^{15} n_{eq}/cm^2$ and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time. In addition to thoroughly describing the setup, we present first predictions for basic pixel cluster properties alongside...

  3. Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

    CERN Document Server

    Rossini, Lorenzo; The ATLAS collaboration

    2018-01-01

    Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of 10^15 neq/cm^2 and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current and future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time and considers both planar and 3D sensor designs. In addition to thoroughly describing the setup, we compare predictions for b...

  4. Modeling radiation damage to pixel sensors in the ATLAS detector

    CERN Document Server

    Ducourthial, Audrey; The ATLAS collaboration

    2017-01-01

    Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of $10^{15}n_{eq}/cm^2$ and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time. In addition to thoroughly describing the setup, we present first predictions for basic pixel cluster properties alongside ...

  5. Modeling radiation damage to pixel sensors in the ATLAS detector

    Science.gov (United States)

    Ducourthial, A.

    2018-03-01

    Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC) . As the closest detector component to the interaction point, these detectors will be subject to a significant amount of radiation over their lifetime: prior to the High-Luminosity LHC (HL-LHC) [1], the innermost layers will receive a fluence in excess of 1015 neq/cm2 and the HL-LHC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is essential in order to make accurate predictions for current and future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects on the ATLAS pixel sensors for the first time. In addition to thoroughly describing the setup, we present first predictions for basic pixel cluster properties alongside early studies with LHC Run 2 proton-proton collision data.

  6. Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

    CERN Document Server

    Rossini, Lorenzo; The ATLAS collaboration

    2018-01-01

    Silicon pixel detectors are at the core of the current and planned upgrade of the ATLAS detector at the Large Hadron Collider (LHC). As the closest detector component to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the High- Luminosity LHC (HL-LHC), the innermost layers will receive a fluence in excess of 10^15 neq/cm2 and the HL-HLC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. Simulating radiation damage is critical in order to make accurate predictions for current future detector performance that will enable searches for new particles and forces as well as precision measurements of Standard Model particles such as the Higgs boson. We present a digitization model that includes radiation damage effects to the ATLAS pixel sensors for the first time and considers both planar and 3D sensor designs. In addition to thoroughly describing the setup, we compare predictions for basic...

  7. An approach to modelling radiation damage by fast ionizing particles

    International Nuclear Information System (INIS)

    Thomas, G.E.

    1987-01-01

    The paper presents a statistical approach to modelling radiation damage in small biological structures such as enzymes, viruses, and some cells. Irreparable damage is assumed to be caused by the occurrence of ionizations within sensitive regions. For structures containing double-stranded DNA, one or more ionizations occurring within each strand of the DNA will cause inactivation; for simpler structures without double-stranded DNA a single ionization within the structure will be sufficient for inactivation. Damaging ionizations occur along tracks of primary irradiating particles or along tracks of secondary particles released at primary ionizations. An inactivation probability is derived for each damage mechanism, expressed in integral form in terms of the radius of the biological structure (assumed spherical), rate of ionization along primary tracks, and maximum energy for secondary particles. The performance of each model is assessed by comparing results from the model with those derived from data from various experimental studies extracted from the literature. For structures where a single ionization is sufficient for inactivation, the model gives qualitatively promising results; for larger more complex structures containing double-stranded DNA, the model requires further refinements. (author)

  8. Importance of the neutron spectrum for determination of radiation damage

    International Nuclear Information System (INIS)

    Hehn, G.; Stiller, P.; Mattes, M.

    1977-01-01

    Since the radiation effects of neutrons depend strongly on the neutron energy, the correlation between the induced damage and the fluence of the fast neutrons shows appreciable disadvantages. The measured values of changes in material properties resulted in large differences for the same fast neutron fluence, being partly due to different neutron spectra. The uncertainties in damage data led to strong overdesign of important structural components. Different neutron environment at surveillance sample position may give an underestimation of the embrittlement in the reactor pressure vessel, which has to be avoided. The application of damage functions combined with accurately calculated neutron spectra, promise to be a reasonable solution. The damage function has the advantage of a phenomenological quantity that all spectral effects are included. But the correlation quantity has to be determined of high experimental costs. Therefore approximations of its energy distributions are very important. For the keV energy region the kerma function is reasonably good. For the MeV energy region a higher effort is needed to calculate the displacement cross section. The same holds for the low energy part. In all three parts the formation of stable material property levels may vary, so that the final correlation can be determined only by measurements of material properties in different neutron spectra. In material samples the spectra distribution of the displacement production rate was determined at different local positions outside the reactor core of a PWR and a fast breeder showing the most important energy regions of both reactors. (orig.) [de

  9. Repair of radiation damage caused by cyclotron-produced neutrons

    International Nuclear Information System (INIS)

    Martins, B.I.

    1979-01-01

    Hall et al. present experimental data on repair of sublethal damage in cultured mammalian cells exposed to 35 MeV neutrons and 60 Co γ rays. Hall and Kraljevic present experimental data on repair of potentially lethal damage in cultured mammalian cells exposed to 35 MeV neutrons and 210 kVp x rays. These results of Hall et al. are very difficult to explain from basic concepts in radiobiology. Contrary to Rossi, these data do not support his thesis that repair of radiation damage is dose-dependent and linear energy transfer independent. Nor do these results meet the expectations of multitarget-single hit theory which would require dose-independent repair equal to n. The observation of the same extrapolation number for neutrons and for x rays is also surprising. From the point of view of radiotherapy, the doses of interest are about 140 rad for neutrons and about 300 rad for x rays. There are no data for repair of potentially lethal damage below 800 rad for x rays and 400 rad for neutrons. The difference in survival between single and split dose is negligible up to a total of about 600 rad of x rays or of neutrons. These data of Hall et al. therefore have little significance to radiotherapists and are an enigma to radiobiologists

  10. Long-term radiation damage to a spaceborne germanium spectrometer

    CERN Document Server

    Kurczynski, P; Hull, E L; Palmer, D; Harris, M J; Seifert, H; Teegarden, B J; Gehrels, N; Cline, T L; Ramaty, R; Sheppard, D; Madden, N W; Luke, P N; Cork, C P; Landis, D A; Malone, D F; Hurley, K

    1999-01-01

    The Transient Gamma-Ray Spectrometer aboard the Wind spacecraft in deep space has observed gamma-ray bursts and solar events for four years. The germanium detector in the instrument has gradually deteriorated from exposure to the approx 10 sup 8 p/cm sup 2 /yr(>100 MeV) cosmic-ray flux. Low-energy tailing and loss of efficiency, attributed to hole trapping and conversion of the germanium from n- to p-type as a result of crystal damage, were observed. Raising the detector bias voltage ameliorated both difficulties and restored the spectrometer to working operation. Together, these observations extend our understanding of the effects of radiation damage to include the previously unsuccessfully studied regime of long-term operation in space. (author)

  11. Design of Kartini reactor radiation monitor system using lab view

    International Nuclear Information System (INIS)

    Adi Abimanyu; Jumari; Achmad Fahrul Aji; Muhammad Khoiri

    2014-01-01

    Kartini Reactor operation will result in radiation exposure. Gamma radiation exposure rate at the Kartini Reactor monitored by several radiation monitors (Ludlum) that integrate with the computer, so that the rate of radiation exposure is always monitored. Current monitoring system combines six radiation monitor in one computer monitor radiation, and monitoring performed by operators and supervisors to see how the radiation exposure rate measured in the area around the reactor core in a periodic time manually. This research will develop a system to monitor radiation exposure in Kartini reactor based ATMega8 micro controller for interface between radiation monitor and computer and also Graphical User Interface (GUI) develop using Lab view software that makes monitoring is easier and documented regularly. This system is testing by simulation, it is done by replacing the function of the radiation monitoring devices (Ludlum) in Kartini Reactor with computers that send serial data with the same format with a format that is sent by Ludlum. The results show that the interface system has the ability to operate in a range of baud rate 1,200 bps, 2,400 bps, 4,800 bps, 9,600 bps, 14,400 bps, 19,200 bps and 38,400 bps, with the ability to provide realtime information every 6 seconds and able to document the rate of exposure to radiation in the form of logbook. (author)

  12. Suggestions for the Improvement of Environmental Radiation Monitoring in Kenya

    International Nuclear Information System (INIS)

    Shadrack, A. K.

    2012-01-01

    Environmental radiation monitoring in Kenya was started in 1990 following the 1979 Three Mile Island and the 1986 Chernobyl nuclear power plants accidents. The main purpose was to measure the radioactivity of foodstuffs imported from oversees and to carry out environmental radiation monitoring of soil, rock, water and air sample to check for contamination. Through environmental radiation monitoring, the Food and Environmental Monitoring Section (FEM) of the Kenya Radiation Protection Board (RPB) works to protect the public and environment from hazards associated with ionizing radiation. The purpose of this paper was to highlight suggestions for the improvement of environmental radiation monitoring in Kenya with respect to protecting the public and the environment against undue radiation risk by ensuring that potential exposures are kept As Low As Reasonably Achievable (ALARA). The suggestions for improvement will serve as a guideline for the strengthening of environmental radiation monitoring program in Kenya

  13. Compilation of radiation damage test data cable insulating materials

    CERN Document Server

    Schönbacher, H; CERN. Geneva

    1979-01-01

    This report summarizes radiation damage test data on commercially available organic cable insulation and jacket materials: ethylene- propylene rubber, Hypalon, neoprene rubber, polyethylene, polyurethane, polyvinylchloride, silicone rubber, etc. The materials have been irradiated in a nuclear reactor to integrated absorbed doses from 5*10/sup 5/ to 5*10/sup 6/ Gy. Mechanical properties, e.g. tensile strength, elongation at break, and hardness, have been tested on irradiated and non-irradiated samples. The results are presented in the form of tables and graphs, to show the effect of the absorbed dose on the measured properties. (13 refs).

  14. The cost of the radiation damage by the ALARA conception

    International Nuclear Information System (INIS)

    Kononovich, A.L.; Nosov, A.V.; Ivanov, A.V.; Pechkurov, A.V.

    2000-01-01

    A basis for the determination of the cost of the radiation risk as a method for its optimization are given. The correlation between different components of the risk is considered. The aim for optimization as a requirement on decrease of the cumulative risk is formulated. The reliability in the use of mathematic modelling on the determination of the cost of the risk and damage is noted. The lines of approach to determination of the cost of the risk based on the direct analysis of financial expenses are proposed. The results of estimation of the cost of the risk are given. The use of suggested approach is demonstrated on a hypothetical example [ru

  15. Effects of radiation damage on the silicon lattice

    Science.gov (United States)

    Dumas, Katherine A.; Lowry, Lynn; Russo, O. Louis

    1987-01-01

    Silicon was irradiated with both proton and electron particle beams in order to investigate changes in the structural and optical properties of the lattice as a result of the radiation damage. Lattice expansions occurred when large strain fields (+0.34 percent) developed after 1- and 3-MeV proton bombardment. The strain was a factor of three less after 1-MeV electron irradiation. Average increases of approximately 22 meV in the 3.46-eV interband energy gap and 14 meV in the Lorentz broadening parameter were measured after the electron irradiation.

  16. Radiation damage in an amorphous Lennard-Jones solid

    International Nuclear Information System (INIS)

    Chaki, T.K.; Li, J.C.M.

    1985-01-01

    A molecular-dynamics simulation of radiation damage in an amorphous Lennard-Jones solid has been undertaken. A three-dimensional structure of 685 atoms with periodic boundary conditions was used. An atom was injected inward from the middle of one surface, and as it lost its energy its velocity and position were recorded. The temperature profile around the injection direction was also calculated. The amorphous structure was examined before and after irradiation by calculating the volume distribution of the Voronoi polyhedra and its time evolution. The production of vacancies and interstitials was observed. The interstitials were found to disappear rapidly, and the vacancies slowly. (author)

  17. Radiation damage assessment by digital correlation of images

    International Nuclear Information System (INIS)

    Frank, J.; Salih, S.M.; Cosslett, V.E.

    1974-01-01

    Structural changes in the electron microscopic specimen due to radiation damage are conveniently studied by electron diffraction. However, two disadvantages of this method are that it does not work for amorphous specimens and that it is not sensitive to structural changes that affect only the phase of the structure factor. It has been proposed that a series of successive images taken under minimum exposure conditions could provide additional information in those cases where the relationship between object function and image intensity can be established. In order to test the proposed method, both lattice images and diffraction patterns of coronene crystals were recorded in separate experiments at controlled levels of exposure. (author)

  18. The annealing of radiation damage in type Ia diamond

    International Nuclear Information System (INIS)

    Collins, Alan T; Kiflawi, Isaac

    2009-01-01

    The kinetics of the recovery of radiation damage in type Ia diamond has been investigated using isothermal annealing at 600 deg. C. In diamonds having a reasonably homogeneous distribution of nitrogen the decay of the vacancy concentration with time can be approximately described by a single exponential. Previous investigations have identified 'fast' and 'slow' components in the annealing, and we show that the existence of more than one time constant is associated with inhomogeneous nitrogen concentrations. The measurements show further that, in order to obtain the oscillator strengths of nitrogen-vacancy centres, studies must be restricted to diamonds with moderately high nitrogen concentrations.

  19. Protection of DPPC phospholipid liposomal membrane against radiation oxidative damage by antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Marathe, D.L.; Pandey, B.N.; Mishra, K.P [Bhabha Atomic Research Centre, Mumbai (India)

    2000-05-01

    Investigations in our laboratory on egg lecithin liposomes have recently showed a marked protection against damage by gamma radiation when cholesterol was present in the composition of vesicles suggesting a role of bilayer molecular architecture in the mechanism of free radical mediated lipid peroxidation. Present study was designed to determine the changes in bilayer permeability in DPPC unilamelar vesicles after exposure to gamma radiation by monitoring the leakage of pre-loaded carboxyfluorescein (CF), a marker loaded in aqueous interior of vesicle and fluidity alterations in the bilayer using fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), a membrane bilayer probe. It was found that radiation doses of an order of magnitude higher were required to produce detectable changes in vesicles of DPPC than in the vesicles of egg lecithin suggesting a modulating role of chemical nature of composition in the membrane radiation sensitivity. It was significant to find that the leakage of CF from and incorporation of DPH into vesicle bilayer showed similar response pattern to radiation doses (0.1-6 kGy) which was also found to be dose rate dependent. Presence of antioxidants; alpha-tocopherol (0.15 mole %) in the bilayer membrane or ascorbic acid (0.1 mM) in the aqueous region significantly protected DPPC vesicles from radiation damage as determined from DPH uptake kinetics suggesting involvement of reactive free radicals of lipids as well as water radicals in the mechanism of membrane peroxidative damage. The magnitude of protection was found to increase with the increasing concentration of both these antioxidants but comparisons showed that {alpha}-tocopherol was far more effective in protecting the vesicles than ascorbic acid. These results contribute to our understanding of the mechanism of radiation oxidative damage and its modification by radical scavenging and/or organizational modulation which emphasize the importance of structure and composition of

  20. Protection of DPPC phospholipid liposomal membrane against radiation oxidative damage by antioxidants

    International Nuclear Information System (INIS)

    Marathe, D.L.; Pandey, B.N.; Mishra, K.P

    2000-01-01

    Investigations in our laboratory on egg lecithin liposomes have recently showed a marked protection against damage by gamma radiation when cholesterol was present in the composition of vesicles suggesting a role of bilayer molecular architecture in the mechanism of free radical mediated lipid peroxidation. Present study was designed to determine the changes in bilayer permeability in DPPC unilamelar vesicles after exposure to gamma radiation by monitoring the leakage of pre-loaded carboxyfluorescein (CF), a marker loaded in aqueous interior of vesicle and fluidity alterations in the bilayer using fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH), a membrane bilayer probe. It was found that radiation doses of an order of magnitude higher were required to produce detectable changes in vesicles of DPPC than in the vesicles of egg lecithin suggesting a modulating role of chemical nature of composition in the membrane radiation sensitivity. It was significant to find that the leakage of CF from and incorporation of DPH into vesicle bilayer showed similar response pattern to radiation doses (0.1-6 kGy) which was also found to be dose rate dependent. Presence of antioxidants; alpha-tocopherol (0.15 mole %) in the bilayer membrane or ascorbic acid (0.1 mM) in the aqueous region significantly protected DPPC vesicles from radiation damage as determined from DPH uptake kinetics suggesting involvement of reactive free radicals of lipids as well as water radicals in the mechanism of membrane peroxidative damage. The magnitude of protection was found to increase with the increasing concentration of both these antioxidants but comparisons showed that α-tocopherol was far more effective in protecting the vesicles than ascorbic acid. These results contribute to our understanding of the mechanism of radiation oxidative damage and its modification by radical scavenging and/or organizational modulation which emphasize the importance of structure and composition of

  1. Environmental radiation monitoring around the nuclear facilities

    International Nuclear Information System (INIS)

    Lee, H.D.; Lee, Y.B.; Lee, W.Y.; Park, D.W.; Chung, B.G.

    1980-01-01

    For the KAERI site, various environmental samples were collected three times a month, and the natural environmental radiation levels were also measured at each sampling point. Measurements for gross alpha and beta radioactivities of the samples were routinely measured for all samples. Strontium-90 concentrations were also analysed for the fallout and air samples collected daily basis on the roof of the main building. Accumulated exposure including the possibility of determination of low level environmental radiation field by employing thermoluminescent dosimeter, CaSO 4 : Dsub(y)-0.4 teflon disc type, at 6 posts in on-site of the KAERI. As for Kori site, at 19 points of ON, OFF-site, and at the same time the environmental radiation exposure rate at each sampling point were measured. Several environmental samples such as surface soil, pine needles, water samples, milk sample and pasture samples were collected and analysed on a quarterly basis. As a result of the survey it can be said that no significant release of radiation to the environment due to the operations of nuclear facilities including research reactor at the KAERI and power reactor at the Kori has been found during the period of the survey and monitoring. (author)

  2. Monitoring of radiation exposure. Annual report 2000

    International Nuclear Information System (INIS)

    Rantanen, E.

    2001-03-01

    At the end of 2000, there were 1,779 valid safety licenses in Finland for the use of radiation. In addition, there were 2,038 responsible parties for dental x-ray diagnostics. The registry Radiation and Nuclear Safety Authority (STUK) listed 13,754 radiation sources and 270 radionuclide laboratories. In the year 2000 360 inspections were made concerning the safety licences and 53 concerning dental x-ray diagnostics. The import of radioactive substances amounted to 175,836 GBq and export to 74,420 GBq. Short-lived radionuclides produced in Finland amounted to 55,527 GBq. In the year 2000 there were 10,846 workers monitored for radiation exposure at 1,171 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The annual effective dose limit was not exceeded. The total dose recorded in the dose registry(sum of the individual dosemeter readings) was 6.5 Sv in 2000

  3. Molecular dynamics simulation of radiation damage cascades in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Buchan, J. T. [Department of Physics and Astronomy, Curtin University, Perth, Western Australia 6845 (Australia); Robinson, M. [Nanochemistry Research Institute, Curtin University, Perth, Western Australia 6845 (Australia); Christie, H. J.; Roach, D. L.; Ross, D. K. [Physics and Materials Research Centre, School of Computing, Science and Engineering, University of Salford, Salford, Greater Manchester M5 4WT (United Kingdom); Marks, N. A. [Department of Physics and Astronomy, Curtin University, Perth, Western Australia 6845 (Australia); Nanochemistry Research Institute, Curtin University, Perth, Western Australia 6845 (Australia)

    2015-06-28

    Radiation damage cascades in diamond are studied by molecular dynamics simulations employing the Environment Dependent Interaction Potential for carbon. Primary knock-on atom (PKA) energies up to 2.5 keV are considered and a uniformly distributed set of 25 initial PKA directions provide robust statistics. The simulations reveal the atomistic origins of radiation-resistance in diamond and provide a comprehensive computational analysis of cascade evolution and dynamics. As for the case of graphite, the atomic trajectories are found to have a fractal-like character, thermal spikes are absent and only isolated point defects are generated. Quantitative analysis shows that the instantaneous maximum kinetic energy decays exponentially with time, and that the timescale of the ballistic phase has a power-law dependence on PKA energy. Defect recombination is efficient and independent of PKA energy, with only 50% of displacements resulting in defects, superior to graphite where the same quantity is nearly 75%.

  4. Modeling Radiation Damage to Pixel Sensors in the ATLAS Detector

    CERN Document Server

    Nachman, Benjamin Philip; The ATLAS collaboration

    2017-01-01

    Silicon Pixel detectors are at the core of the current and planned upgrade of the ATLAS detector. As the detector in closest proximity to the interaction point, these detectors will be subjected to a significant amount of radiation over their lifetime: prior to the HL-LHC, the innermost layers will receive a fluence in excess of $10^{15}$ 1 MeV $n_\\mathrm{eq}/\\mathrm{cm}^2$ and the HL-LHC detector upgrades must cope with an order of magnitude higher fluence integrated over their lifetimes. This talk presents a digitization model that includes radiation damage effects to the ATLAS Pixel sensors for the first time. After a thorough description of the setup, predictions for basic Pixel cluster properties are presented alongside first validation studies with Run 2 collision data.

  5. Radiation ecological monitoring in NPP region

    International Nuclear Information System (INIS)

    Egorov, Yu.A.; Kazakov, S.V.

    1985-01-01

    The known principle of sanitary-hygienic regulation of NPP radiation effect on man and environment is analyzed. An ecological approach is required to optimize NPP relations with the environment and to regulate radioactivity of the NPP - environment system. The ecological approach envisages the development of standards of permissible concentrations of radioactive and chemical substances (as well as heat) in natural environment, taking into account their synergism, corresponding to ecologically permissible response reactions of biota to their effect. The ecological approach also comprises the sanitary-hygienic principle of radiation protection of man. Attention is paid to ecological monitoring in NPP region, comprising consideration of factors, affecting the environment, evaluation of the actual state of the environment, prediction of the environmental state, evaluation of the expected environmental state

  6. Mobile units for monitoring of radiation situation

    International Nuclear Information System (INIS)

    Drabova, D.; Filgas, R.; Cespirova, I.

    1995-01-01

    For the radiation monitoring network of the Czech Republic a prototype of the small system for dose rate measurements and nuclide activity estimates suitable for use in mobile units was designed and tested in National Radiation Protection Institute. The system consists of high purity Ge detector, multichannel analyzer, high pressure ionization chamber or proportional counter and portable computer working in multitask mode for storing and evaluating of the spectra as well as dose rate handling, recording, storing and searching and presentation. The information about actual position is provided by the global positioning system Garmin on-line connected to the computer. This information is used later on to create the maps of contamination using small desktop mapping (GIS) system. The system is designed to be used in measurements on foot, in car, with helicopter or small fixed wing aircraft. (J.K.)

  7. A new system for radiation monitoring

    International Nuclear Information System (INIS)

    Toivonen, H.

    1993-01-01

    The Finnish authorities are acquiring a new radiation monitoring system enabling realtime transmission of information on the radiation situation. The system will also gather meteorological data and make predictions on the movements of a radioactive cloud. The data are stored in a database, from which they can be retrieved onto a user's workstation. Each user can get an overall picture of the current situation by viewing a set of files which are produced automatically by the system. Upon receiving notice of a hazard, the system contacts the paging devices of the officers on call. When the notice comes from a single station, the system automatically reads the measurement data of all stations within 50 kilometers. The system, development of which began in 1992, will be put to use early next year. (orig.)

  8. Occupational radiation exposure in Germany: many monitored persons = high exposure?

    International Nuclear Information System (INIS)

    Nitschke, J.

    1996-01-01

    Natural radiation affects the entire population in Germany, and most of Germany's inhabitants are exposed to medical radiation in their lifetime. Occupational radiation exposure, however, is a kind of exposure affecting only a limited and well-defined group of the population, and this radiation exposure has been recorded and monitored as precisely as technically possible ever since the radiation protection laws made occupational radiation exposure monitoring a mandatory obligation. Official personal dosimetry applying passive dosemeters in fact does not offer direct protection against the effects of ionizing radiation, as dosemeter read-out and dose calculation is a post-exposure process. But it nevertheless is a rewarding monitoring duty under radiation protection law, as is shown by the radiation exposure statistics accumulated over decades: in spite of the number of monitored persons having been increasing over the years, the total exposure did not, due to the corresponding improvements in occupational radiation protection. (orig.) [de

  9. Cryogenic semiconductor high-intensity radiation monitors

    International Nuclear Information System (INIS)

    Palmieri, V.G.; Bell, W.H.; Borer, K.; Casagrande, L.; Da Via, C.; Devine, S.R.H.; Dezillie, B.; Esposito, A.; Granata, V.; Hauler, F.; Jungermann, L.; Li, Z.; Lourenco, C.; Niinikoski, T.O.; Shea, V. O'; Ruggiero, G.; Sonderegger, P.

    2003-01-01

    This paper describes a novel technique to monitor high-intensity particle beams by means of a semiconductor detector. It consists of cooling a semiconductor detector down to cryogenic temperature to suppress the thermally generated leakage current and to precisely measure the integrated ionization signal. It will be shown that such a device provides very good linearity and a dynamic range wider than is possible with existing techniques. Moreover, thanks to the Lazarus effect, extreme radiation hardness can be achieved providing in turn absolute intensity measurements against precise calibration of the device at low beam flux

  10. Intercomparison of radiation dosimeters for individual monitoring

    International Nuclear Information System (INIS)

    1993-05-01

    The Co-ordinated Research Programme on Intercomparison for Individual Monitoring was established to provide participants with an opportunity to assess (1) their ability to measure external photon radiation fields and (2) the potential impact of introduction of the new operational quantities on their dosimetry programmes. Twenty-four laboratories from 18 IAEA Member States and three international organizations, including the IAEA, participated. The results of phase II of the CRP are presented in this document, which includes a compilation of the presentations and conclusions from the meeting. Refs, figs and tabs

  11. Environmental radiation monitoring around the nuclear facilities

    International Nuclear Information System (INIS)

    Lee, H.D.; Lee, W.Y.; Park, D.W.

    1981-01-01

    Measurements and monitoring of the environmental radiation levels, as well as radioactivity of the various environmental samples were carried out three times a month in the on-site and the off-site around the KAERI site. Measurements were made for both gross alpha and beta radioactivity of all environmental samples. Gross beta measurements were made for radioactivity of the fallout, airborne particulates and precipitations which were collected on a daily basis on the roof of the main building. Measurements of the accumulated doses were also carried out at 10 posts on a bimonthly basis by employing thermoluminescent dosimeters

  12. The LISA Pathfinder DMU and Radiation Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Canizares, P; Conchillo, A; Gesa, L; Lloro, I; Lobo, A; Mateos, I; Sopuerta, Carlos F [Institut de Ciencies de l' Espai, CSIC, Facultat de Ciencies, Torre C5 parell, 08193 Bellaterra (Spain); Chmeissani, M [Institut de Fisica d' Altes Energies (IFAE), Edifici CN, UAB Campus, 08193 Bellaterra (Spain); Diaz-Aguilo, M; GarcIa-Berro, E; Gibert, F [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Grimani, C [Universita degli Studi di Urbino, MFI Department, Via Santa Chiara 27, 61029 Urbino, and INFN Florence (Italy); Nofrarias, M [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, D-30167 Hannover (Germany); Ramos-Castro, J [Departament d' Enginyeria Electronica, UPC, Campus Nord, Edifici C4, Jordi Girona 1-3, 08034 Barcelona (Spain); Sanjuan, J [Department of Physics, University of Florida, NPB-22258 PO Box 118 440, Gainesville, FL 32611-8440 (United States); Araujo, H M; Wass, P, E-mail: lobo@ieec.fcr.es [High Energy Physics Blackett Laboratory, Prince Consort Road, Imperial College London, London SW7 2BW (United Kingdom)

    2011-05-07

    The LISA Pathfinder DMU (Data Management Unit) flight model was formally accepted by ESA and ASD on 11 February 2010, after all hardware and software tests had been successfully completed. The diagnostics items are scheduled to be delivered by the end of 2010. In this paper, we review the requirements and performance of this instrumentation, specially focusing on the Radiation Monitor and the DMU, as well as the status of their programmed use during mission operations, on which work is ongoing at the time of writing.

  13. Properties and recrystallization of radiation damaged pyrochlore and titanite

    Energy Technology Data Exchange (ETDEWEB)

    Zietlow, Peter

    2016-11-02

    Radiation damage in minerals is caused by the alpha-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400-1400 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG) (Zietlow et al., in print). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia (6.4 wt% Th, 23.1.10{sup 18} a-decay events per gram (dpg)), Zlatoust/Russia (6.3 wt% Th, 23.1.10{sup 18} dpg), Panda Hill/Tanzania (1.6 wt% Th, 1.6.10{sup 18} dpg), and Blue River/Canada (10.5 wt% U, 115.4.10{sup 18} dpg), are compared with a crystalline reference pyrochlore from Schelingen (Germany). The type of structural recovery depends on the initial degree of radiation damage (Panda Hill 28 %, Blue River 85 %, Zlatoust and Miass 100 % according to XRD), as the recrystallization temperature increases with increasing degree of amorphization. Raman spectra indicate reordering on the local scale during annealing-induced recrystallization. As Raman modes around 800 cm{sup -1} are sensitive to radiation damage (Vandenborre and Husson 1983, Moll et al. 2011), the degree of local order was deduced from the ratio of the integrated intensities of the sum of the Raman bands between 605 and 680 cm{sup -1} devided by the sum of the integrated intensities of the bands between 810 and 860 cm{sup -1}. The most radiation damaged pyrochlores (Miass and Zlatoust) show an abrupt recovery of both, its short- (Raman) and long-range order (X-ray) between 800 and 850 K. The volume decrease upon recrystallization in Zlatoust pyrochlore was large enough to crack the sample repeatedly. In contrast, the weakly damaged pyrochlore (Panda Hill) begins to recover at considerably lower temperatures (near 500 K), extending over a temperature range of ca. 300 K, up to 800 K (Raman). The pyrochlore from Blue River shows in its

  14. Quantitative radiation monitors for containment and surveillance

    International Nuclear Information System (INIS)

    Fehlau, P.E.

    1983-01-01

    Quantitative radiation monitors make it possible to differentiate between shielded and unshielded nuclear materials. The hardness of the gamma-ray spectrum is the attribute that characterizes bare or shielded material. Separate high- and low-energy gamma-ray regions are obtained from a single-channel analyzer through its window and discriminator outputs. The monitor counts both outputs and computes a ratio of the high- and low-energy region counts whenever an alarm occurs. The ratio clearly differentiates between shielded and unshielded nuclear material so that the net alarm count may be identified with a small quantity of unshielded material or a large quantity of shielded material. Knowledge of the diverted quantity helps determine whether an inventory should be called to identify the loss

  15. Radiation monitoring system based on Internet

    International Nuclear Information System (INIS)

    Drndarevic, V.R.; Popovic, A.T; Bolic, M.D.; Pavlovic, R.S.

    2001-01-01

    This paper presents concept and realization of the modern distributed radiation monitoring system. The system uses existing conventional computer network and it is based on the standard Internet technology. One personal computer (PC) serves as host and system server, while a number of client computers, link to the server computer via standard local area network (LAN), are used as distributed measurement nodes. The interconnection between the server and clients are based on Transmission Control Protocol/Internet Protocol (TCP/IP). System software is based on server-client model. Based on this concept distributed system for gamma ray monitoring in the region of the Institute of Nuclear Sciences Vinca has been implemented. (author)

  16. Software for airborne radiation monitoring system

    International Nuclear Information System (INIS)

    Sheinfeld, M.; Kadmon, Y.; Tirosh, D.; Elhanany, I.; Gabovitch, A.; Barak, D.

    1997-01-01

    The Airborne Radiation Monitoring System monitors radioactive contamination in the air or on the ground. The contamination source can be a radioactive plume or an area contaminated with radionuclides. This system is composed of two major parts: Airborne Unit carried by a helicopter, and Ground Station carried by a truck. The Airborne software is intended to be the core of a computerized airborne station. The software is written in C++ under MS-Windows with object-oriented methodology. It has been designed to be user-friendly: function keys and other accelerators are used for vital operations, a help file and help subjects are available, the Human-Machine-Interface is plain and obvious. (authors)

  17. Radiation damage on sub-cellular scales: beyond DNA

    International Nuclear Information System (INIS)

    Byrne, H L; McNamara, A L; Domanova, W; Kuncic, Z; Guatelli, S

    2013-01-01

    This study investigates a model cell as a target for low-dose radiation using Monte Carlo simulations. Mono-energetic electrons and photons are used with initial energies between 10 and 50 keV, relevant to out-of-field radiotherapy scenarios where modern treatment modalities expose relatively large amounts of healthy tissue to low-dose radiation, and also to microbeam cell irradiation studies which show the importance of the cytoplasm as a radiation target. The relative proportions of number of ionizations and total energy deposit in the nucleus and cytoplasm are calculated. We show that for a macroscopic dose of no more than 1 Gy only a few hundred ionizations occur in the nucleus volume whereas the number of ionizations in the cytoplasm is over a magnitude larger. We find that the cell geometry can have an appreciable effect on the energy deposit in the cell and can cause a nonlinear increase in energy deposit with cytoplasm density. We also show that changing the nucleus volume has negligible effect on the total energy deposit but alters the relative proportion deposited in the nucleus and cytoplasm; the nucleus volume must increase to approximately the same volume as the cytoplasm before the energy deposit in the nucleus matches that in the cytoplasm. Additionally we find that energy deposited by electrons is generally insensitive to spatial variations in chemical composition, which can be attributed to negligible differences in electron stopping power for cytoplasm and nucleus materials. On the other hand, we find that chemical composition can affect energy deposited by photons due to non-negligible differences in attenuation coefficients. These results are of relevance in considering radiation effects in healthy cells, which tend to have smaller nuclei. Our results further show that the cytoplasm and organelles residing therein can be important targets for low-dose radiation damage in healthy cells and warrant investigation as much as the conventional focus

  18. Radiation monitoring with CVD diamonds and PIN diodes at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Bruinsma, M. [University of California Irvine, Irvine, CA 92697 (United States); Burchat, P. [Stanford University, Stanford, CA 94305-4060 (United States); Curry, S. [University of California Irvine, Irvine, CA 92697 (United States)], E-mail: scurry@slac.stanford.edu; Edwards, A.J. [Stanford University, Stanford, CA 94305-4060 (United States); Kagan, H.; Kass, R. [Ohio State University, Columbus, OH 43210 (United States); Kirkby, D. [University of California Irvine, Irvine, CA 92697 (United States); Majewski, S.; Petersen, B.A. [Stanford University, Stanford, CA 94305-4060 (United States)

    2007-12-11

    The BaBar experiment at the Stanford Linear Accelerator Center has been using two polycrystalline chemical vapor deposition (pCVD) diamonds and 12 silicon PIN diodes for radiation monitoring and protection of the Silicon Vertex Tracker (SVT). We have used the pCVD diamonds for more than 3 years, and the PIN diodes for 7 years. We will describe the SVT and SVT radiation monitoring system as well as the operational difficulties and radiation damage effects on the PIN diodes and pCVD diamonds in a high-energy physics environment.

  19. Continuous environmental radiation monitoring network at Kalpakkam

    International Nuclear Information System (INIS)

    Somayaji, K.M.; Mathiyarasu, R.; Prakash, G.S.; Meenakshisundaram, V.; Rajagopal, V.

    1997-01-01

    The report highlights our experience in the design and installation of monitoring stations as part of continuous environmental radiation monitoring network around the periphery of the nuclear complex at Kalpakkam. Five monitoring stations, one each in south-west sector (Main Gate I) and south-south west (Main Gate II) and the others in North sector (HASL and ESG) and in north-west section (WIP) have been set up. Two independent detector systems, based on high pressure ionisation chamber (HPIC) and energy compensated GM have been installed at each of these locations and the data has been logged continuously using a data logger. The data so gathered at each monitoring station is retrieved every week by means of a hand held terminal (HHT) with a built-in non-volatile memory and transferred to an IBM PC-AT for data analysis and archival. The report discusses in depth the design and developmental efforts undertaken to set up the network, starting from the basic detectors. The work involved the design of suitable electrometer circuits for measuring the low levels of current from HPICs, and the subsequent study of the performance of the highly sensitive preamplifier under diurnal variations of ambient conditions. The report includes, in detail the design aspects and fabrication details of low current measuring electrometer circuits

  20. Special nuclear material radiation monitors for the 1980's

    International Nuclear Information System (INIS)

    Fehlau, P.E.

    1985-01-01

    During the two decades that automatic gamma-radiation monitors have been applied to detecting special nuclear material (SNM), little attention has been devoted to how well the monitors perform in plant environments. Visits to 11 DOE facilities revealed poor information flow between developers, manufacturers, and maintainers of SNM radiation monitors. To help users achieve best performance from their monitors or select new ones, Los Alamos National Laboratory developed a hand-held monitor user's guide, calibration manuals for some commercial SNM pedestrian monitors, and an application guide for SNM pedestrian monitors. In addition, Los Alamos evaluated new commercial SNM monitors, considered whether to apply neutron detection to SNM monitoring, and investigated the problem of operating gamma-ray SNM monitors in variable plutonium gamma-radiation fields. As a result, the performance of existing SNM monitors will improve and alternative monitoring methods will become commerciallly available during the 1980s. 9 refs., 6 figs., 1 tab

  1. Monitoring of Progressive Damage in Buildings Using Laser Scan Data

    Science.gov (United States)

    Puente, I.; Lindenbergh, R.; Van Natijne, A.; Esposito, R.; Schipper, R.

    2018-05-01

    Vulnerability of buildings to natural and man-induced hazards has become a main concern for our society. Ensuring their serviceability, safety and sustainability is of vital importance and the main reason for setting up monitoring systems to detect damages at an early stage. In this work, a method is presented for detecting changes from laser scan data, where no registration between different epochs is needed. To show the potential of the method, a case study of a laboratory test carried out at the Stevin laboratory of Delft University of Technology was selected. The case study was a quasi-static cyclic pushover test on a two-story high unreinforced masonry structure designed to simulate damage evolution caused by cyclic loading. During the various phases, we analysed the behaviour of the masonry walls by monitoring the deformation of each masonry unit. First a plane is fitted to the selected wall point cloud, consisting of one single terrestrial laser scan, using Principal Component Analysis (PCA). Second, the segmentation of individual elements is performed. Then deformations with respect to this plane model, for each epoch and specific element, are determined by computing their corresponding rotation and cloud-to-plane distances. The validation of the changes detected within this approach is done by comparison with traditional deformation analysis based on co-registered TLS point clouds between two or more epochs of building measurements. Initial results show that the sketched methodology is indeed able to detect changes at the mm level while avoiding 3D point cloud registration, which is a main issue in computer vision and remote sensing.

  2. A new cryostat for 'in situ' radiation damage studies

    International Nuclear Information System (INIS)

    Hariharan, Y.; Radhakrishnan, T.S.

    1977-01-01

    Conventional cryostats to study properties of materials between 4deg K and 300deg K base their designs either on continuous flow or bath type. A new cryostat which incorporates the advantages of both these has been designed and fabricated. This essentially has three chambers isolated from each other by poor thermal links. These are enclosed in a vacuum chamber and the whole assembly is immersed in a 4 He bath. The lowermost chamber is kept in good thermal contact with the bath. The second chamber can be maintained between 4deg K and 77deg K by circulation of cold 4 He vapour. The uppermost chamber can be maintained between 77deg K and 300deg K by circulating cold nitrogen vapours. There is a through axial hole in the centre, through which the sample can be moved up and down by means of a thin walled stainless steel tube. This comes out from the top of the cryostat through a Wilson seal. Thus the specimen can be anchored in any of the three chambers. This cryostat can be used to study the radiation damages caused by α-particles the sample being kept at 4.2deg K. There is provision for isolating the sample from the radiation zone. Isothermal and isochronal annealing of the damage caused can also be studied. Provision for taking out electrical leads from both inside and outside the sample chamber are also there. (auth.)

  3. Analysis of radiation damage in on-orbit solar array of Venus explorer Akatsuki

    International Nuclear Information System (INIS)

    Toyota, Hiroyuki; Shimada, Takanobu; Takahashi, You; Imamura, Takeshi; Hada, Yuko; Ishii, Takako T.; Isobe, Hiroaki; Asai, Ayumi; Shiota, Daikou

    2013-01-01

    This paper describes an analysis of radiation damage in solar array of Venus explorer Akatsuki observed on orbit. The output voltage of the solar array have shown sudden drops, which are most reasonably associated with radiation damage, three times since its launch. The analysis of these radiation damages is difficult, because no direct observation data of the spectra and the amount of the high-energy particles is available. We calculated the radiation damage using the relative damage coefficient (RDC) method assuming a typical spectral shape of protons. (author)

  4. Facilities for studying radiation damage in nonmetals during irradiation

    International Nuclear Information System (INIS)

    Levy, P.W.

    1984-08-01

    Two facilities have been developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses 60 Co gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescenc detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and data recording is computerized. Irradiations are made at controlled temperatures between 5K and 900 0 C. The materials studied include glasses, quartz, alkali halides (especially natural rock salt), organic crystals, etc. As determined from color center measurements the damage formation rate in all materials studied at 25 0 C or above is strongly temperature dependent. The defect concentration during irradiation is usually much greater than that measured after irradiation. The fraction of defects annealing after irradiation and the annealing rate usually increases as the irradiation temperature increases. The completed studies demonstrate that, in most cases, the extent of maximum damage and the damage formation and annealing kinetics can be determined only by making measurements during irradiation

  5. Clinical evaluation of direct and photosensitized ultraviolet radiation damage to the lens

    International Nuclear Information System (INIS)

    Hockwin, O.; Lerman, S.

    1982-01-01

    We are reporting a new, objective, and quantitative method for monitoring age-related molecular changes in the human ocular lens in vivo, as expressed by increases in at least two (nontryptophan) fluorescence wavelengths. These fluorescence wavelengths appear to be caused by photochemically induced changes in the lens, and they reflect the ultraviolet (UV) filtering capacity of the patients' ocular lenses. These data correlate with previously reported in vitro lens fluorescence changes that are associated with the aging process. This method will also detect alterations in lenticular fluorescence caused by photosensitized as well as direct UV radiation damage

  6. Longitudinal diffusion tensor magnetic resonance imaging study of radiation-induced white matter damage in a rat model.

    Science.gov (United States)

    Wang, Silun; Wu, Ed X; Qiu, Deqiang; Leung, Lucullus H T; Lau, Ho-Fai; Khong, Pek-Lan

    2009-02-01

    Radiation-induced white matter (WM) damage is a major side effect of whole brain irradiation among childhood cancer survivors. We evaluate longitudinally the diffusion characteristics of the late radiation-induced WM damage in a rat model after 25 and 30 Gy irradiation to the hemibrain at 8 time points from 2 to 48 weeks postradiation. We hypothesize that diffusion tensor magnetic resonance imaging (DTI) indices including fractional anisotropy (FA), trace, axial diffusivity (lambda(//)), and radial diffusivity (lambda( perpendicular)) can accurately detect and monitor the histopathologic changes of radiation-induced WM damage, measured at the EC, and that these changes are dose and time dependent. Results showed a progressive reduction of FA, which was driven by reduction in lambda(//) from 4 to 40 weeks postradiation, and an increase in lambda( perpendicular) with return to baseline in lambda(//) at 48 weeks postradiation. Histologic evaluation of irradiated WM showed reactive astrogliosis from 4 weeks postradiation with reversal at 36 weeks, and demyelination, axonal degeneration, and necrosis at 48 weeks postradiation. Moreover, changes in lambda(//) correlated with reactive astrogliosis (P histopathologic changes of WM damage and our results support the use of DTI as a biomarker to noninvasively monitor radiation-induced WM damage.

  7. Electron Beam Induced Radiation Damage of the Semiconductor Radiation Detector based on Silicon

    International Nuclear Information System (INIS)

    Kim, Han Soo; Kim, Yong Kyun; Park, Se Hwan; Haa, Jang Ho; Kang, Sang Mook; Chung, Chong Eun; Cho, Seung Yeon; Park, Ji Hyun; Yoon, Tae Hyung

    2005-01-01

    A Silicon Surface Barrier (SSB) semiconductor detector which is generally used to detect a charged particle such as an alpha particle was developed. The performance of the developed SSB semiconductor detector was measured with an I-V curve and an alpha spectrum. The response for an alpha particle was measured by Pu-238 sources. A SSB semiconductor detector was irradiated firstly at 30sec, at 30μA and secondly 40sec, 40μA with a 2MeV pulsed electron beam generator in KAERI. And the electron beam induced radiation damage of a homemade SSB detector and the commercially available PIN photodiode were investigated. An annealing effect of the damaged SSB and PIN diode detector were also investigated using a Rapid Thermal Annealing (RTA). This data may assist in designing the silicon based semiconductor radiation detector when it is operated in a high radiation field such as space or a nuclear power plant

  8. Radiation damage characterization in reactor pressure vessel steels with nonlinear ultrasound

    International Nuclear Information System (INIS)

    Matlack, K. H.; Kim, J.-Y.; Wall, J. J.; Qu, J.; Jacobs, L. J.

    2014-01-01

    Nuclear generation currently accounts for roughly 20% of the US baseload power generation. Yet, many US nuclear plants are entering their first period of life extension and older plants are currently undergoing assessment of technical basis to operate beyond 60 years. This means that critical components, such as the reactor pressure vessel (RPV), will be exposed to higher levels of radiation than they were originally intended to withstand. Radiation damage in reactor pressure vessel steels causes microstructural changes such as vacancy clusters, precipitates, dislocations, and interstitial loops that leave the material in an embrittled state. The development of a nondestructive evaluation technique to characterize the effect of radiation exposure on the properties of the RPV would allow estimation of the remaining integrity of the RPV with time. Recent research has shown that nonlinear ultrasound is sensitive to radiation damage. The physical effect monitored by nonlinear ultrasonic techniques is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave, arising from the interaction of the ultrasonic wave with microstructural features such as dislocations, precipitates, and their combinations. Current findings relating the measured acoustic nonlinearity parameter to increasing levels of neutron fluence for different representative RPV materials are presented

  9. Radiation damage characterization in reactor pressure vessel steels with nonlinear ultrasound

    Science.gov (United States)

    Matlack, K. H.; Kim, J.-Y.; Wall, J. J.; Qu, J.; Jacobs, L. J.

    2014-02-01

    Nuclear generation currently accounts for roughly 20% of the US baseload power generation. Yet, many US nuclear plants are entering their first period of life extension and older plants are currently undergoing assessment of technical basis to operate beyond 60 years. This means that critical components, such as the reactor pressure vessel (RPV), will be exposed to higher levels of radiation than they were originally intended to withstand. Radiation damage in reactor pressure vessel steels causes microstructural changes such as vacancy clusters, precipitates, dislocations, and interstitial loops that leave the material in an embrittled state. The development of a nondestructive evaluation technique to characterize the effect of radiation exposure on the properties of the RPV would allow estimation of the remaining integrity of the RPV with time. Recent research has shown that nonlinear ultrasound is sensitive to radiation damage. The physical effect monitored by nonlinear ultrasonic techniques is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave, arising from the interaction of the ultrasonic wave with microstructural features such as dislocations, precipitates, and their combinations. Current findings relating the measured acoustic nonlinearity parameter to increasing levels of neutron fluence for different representative RPV materials are presented.

  10. Radiation monitoring of Syr-Darya river

    International Nuclear Information System (INIS)

    Barber, D.S.; Howard, H.D.; Betsill, J.D.; Matthews, R.; Yuldashev, B.S.; Salikhbaev, U.S.; Radyuk, R.I.; Vdovina, E.D.; Solodukhin, V.P.; Poznyak, V.L.; Vasiliev, I.A.; Alekhina, V.M.; Juraev, A.A.

    2003-01-01

    The article contains the results obtained during the radiation monitoring of Syr-Darya River, which was conducted within the frames of international collaboration of Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, and USA. The data on the nature of salinity of water, alfa- and beta-activity of water, bottom, water plants, and soil was obtained. Dependence of the obtained results on the distance form the source is discussed. The major life-providing arteries for the great region of Central Asia are Syr-Darya and Amu Darya rivers. There are many countries next to the pools of these rivers: Tajikistan, Afghanistan, Turkmenistan, Uzbekistan, Kyrgyzstan, and Kazakhstan. There is a great concern caused by the shortage of supply of fresh water, severe epidemiological situation, and radiation conditions along of the pools of these rivers. Such conditions have developed as a result of intensive economic and industrial activities, and also of geological and geochemical features of this region. One of the most serious aspects of this problem is the weak scrutiny level of influence of large deposits of natural uranium and consequences of technological and industrial activities. Since November, 2000 Scientifics of four of the listed countries (Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan) have come to an agreement carrying out the teamwork on studying and monitoring the environment in the pools of Syr-Darya and Amu Darya rivers [1]. Collaborator of these works is Cooperative Monitoring Center at Sandia National Laboratories, USA. During three expeditions each country in 15 control sites on their territory has conducted field researches and has obtained the samples of elements of the environment. Laboratory researches were carried out in Kazakhstan and Uzbekistan. The first results were obtained in (2,3) and later in [4].Currently, the analysis of the data on salinity of water and alpha- and beta- activities of samples along Syr-Darya River is presented

  11. Rosiglitazone attenuates pulmonary fibrosis and radiation-induced intestinal damage

    International Nuclear Information System (INIS)

    Mangoni, M.; Gerini, C.; Sottili, M.; Cassani, S.; Stefania, G.; Biti, G.; Castiglione, F.; Vanzi, E.; Bottoncetti, A.; Pupi, A.

    2011-01-01

    Full text of publication follows: Purpose.-The aim of the study was to evaluate radioprotective effect of rosiglitazone (RGZ) on a murine model of late pulmonary damage and of acute intestinal damage. Methods.- Lung fibrosis: C57 mice were treated with the radiomimetic agent bleomycin, with or without rosiglitazone (5 mg/kg/day). To obtain an independent qualitative and quantitative measure for lung fibrosis we used high resolution CT, performed twice a week during the entire observation period. Hounsfield Units (HU) of section slides from the upper and lower lung region were determined. On day 31 lungs were collected for histological analysis. Acute intestinal damage: mice underwent 12 Gy total body irradiation with or without rosiglitazone. Mice were sacrificed 24 or 72 h after total body irradiation and ileum and colon were collected. Results.- Lung fibrosis: after bleomycin treatment, mice showed typical CT features of lung fibrosis, including irregular septal thickening and patchy peripheral reticular abnormalities. Accordingly, HU lung density was dramatically increased. Rosiglitazone markedly attenuated the radiological signs of fibrosis and strongly inhibited HU lung density increase (60% inhibition at the end of the observation period). Histological analysis revealed that in bleomycin-treated mice, fibrosis involved 50-55% of pulmonary parenchyma and caused an alteration of the alveolar structures in 10% of parenchyma, while in rosiglitazone-treated mice, fibrosis involved only 20-25% of pulmonary parenchyma, without alterations of the alveolar structures. Acute intestinal damage: 24 h after 12 Gy of total body irradiation intestinal mucosa showed villi shortening, mucosal thickness and crypt necrotic changes. Rosiglitazone showed a histological improvement of tissue structure, with villi and crypts normalization and oedema reduction. Conclusion.- These results demonstrate that rosiglitazone displays a protective effect on pulmonary fibrosis and radiation

  12. Rosiglitazone attenuates pulmonary fibrosis and radiation-induced intestinal damage

    Energy Technology Data Exchange (ETDEWEB)

    Mangoni, M.; Gerini, C.; Sottili, M.; Cassani, S.; Stefania, G.; Biti, G. [Radiotherapy Unit, Clinical Physiopathology Department, University of Florence, Firenze (Italy); Castiglione, F. [Department of Human Pathology and Oncology, University of Florence, Firenze (Italy); Vanzi, E.; Bottoncetti, A.; Pupi, A. [Nuclear Medicine Unit, Clinical Physiopathology Department, University of Florence, Firenze (Italy)

    2011-10-15

    Full text of publication follows: Purpose.-The aim of the study was to evaluate radioprotective effect of rosiglitazone (RGZ) on a murine model of late pulmonary damage and of acute intestinal damage. Methods.- Lung fibrosis: C57 mice were treated with the radiomimetic agent bleomycin, with or without rosiglitazone (5 mg/kg/day). To obtain an independent qualitative and quantitative measure for lung fibrosis we used high resolution CT, performed twice a week during the entire observation period. Hounsfield Units (HU) of section slides from the upper and lower lung region were determined. On day 31 lungs were collected for histological analysis. Acute intestinal damage: mice underwent 12 Gy total body irradiation with or without rosiglitazone. Mice were sacrificed 24 or 72 h after total body irradiation and ileum and colon were collected. Results.- Lung fibrosis: after bleomycin treatment, mice showed typical CT features of lung fibrosis, including irregular septal thickening and patchy peripheral reticular abnormalities. Accordingly, HU lung density was dramatically increased. Rosiglitazone markedly attenuated the radiological signs of fibrosis and strongly inhibited HU lung density increase (60% inhibition at the end of the observation period). Histological analysis revealed that in bleomycin-treated mice, fibrosis involved 50-55% of pulmonary parenchyma and caused an alteration of the alveolar structures in 10% of parenchyma, while in rosiglitazone-treated mice, fibrosis involved only 20-25% of pulmonary parenchyma, without alterations of the alveolar structures. Acute intestinal damage: 24 h after 12 Gy of total body irradiation intestinal mucosa showed villi shortening, mucosal thickness and crypt necrotic changes. Rosiglitazone showed a histological improvement of tissue structure, with villi and crypts normalization and oedema reduction. Conclusion.- These results demonstrate that rosiglitazone displays a protective effect on pulmonary fibrosis and radiation

  13. Synchrotron radiation. 4. Analyses of biological samples using synchrotron radiation. 3. Research on radiation damage to DNA using synchrotron radiation

    International Nuclear Information System (INIS)

    Takakura, Kaoru

    1998-01-01

    This review described how the synchrotron radiation (SR) is used to solve problems unknown hitherto in radiation biology. Historically, the target substance of UV light in bacterial death was suggested to be nucleic acid in 1930. Researches on the radiation damage to DNA were begun at around 1960 and have mainly used UV light, X-ray and γray. Soft X-ray and vacuum UV whose energy covering from several eV to scores of keV have not been used since UV and X-ray lack the energy of this range. This is one of reasons why detailed process leading to radiation-induced death, carcinogenicity and mutation has not been known hitherto. RS possesses wide range of energy, i.e., from UV to hard X-ray, of high intensity, which is helpful for studying the unknown problems. The RS studies were begun in nineteen-seventies. Those include the action spectrum studies and atomic target studies. In the former, the course of the effect, e.g., the mechanism of DNA double strand breakage, can be elucidated. In the latter, photon of known energy can be irradiated to the specified atom like phosphorus in DNA which elucidating the precise physicochemical process of the breakage. Use of RS in these studies is thought still meaningful in future. (K.H.) 62 refs

  14. Radiation damage effects in solids special topic volume with invited peer reviewed papers only

    CERN Document Server

    Virk, Hardev Singh

    2013-01-01

    Public interest and concern about radiation damage effects has increased during recent times. Nuclear radiation proved to be a precursor for the study of radiation damage effects in solids. In general, all types of radiation, e.g. X-ray, gamma ray, heavy ions, fission fragments and neutrons produce damage effects in materials. Radiation damage latent tracks in solids find applications in nuclear and elementary particle physics, chemistry, radiobiology, earth sciences, nuclear engineering, and a host of other areas such as nuclear safeguards, virus counting, ion track filters, uranium exploration and archaeology. Radiation dosimetry and reactor shielding also involve concepts based on radiation damage in solids. This special volume consists of ten Chapters, including Review and Research Papers on various topics in this field.Physical scientists known to be investigating the effects of radiation on material were invited to contribute research and review papers on the areas of their specialty. The topics include...

  15. The development of wireless radiation dose monitoring using smart phone

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Woo; Jeong, Gyo Seong; Lee, Yun Jong [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Chong Yeal [Chonbuk National University, Jeonju (Korea, Republic of); Lim, Chai Wan [REMTECH, Seoul (Korea, Republic of)

    2016-11-15

    Radiation workers at a nuclear facility or radiation working area should hold personal dosimeters. some types of dosimeters have functions to generate audible or visible alarms to radiation workers. However, such devices used in radiation fields these days have no functions to communicate with other equipment or the responsible personnel. our project aims at the development of a remote wireless radiation dose monitoring system that can be utilized to monitor the radiation dose for radiation workers and to notify the radiation protection manager of the dose information in real time. We use a commercial survey meter for personal radiation measurement and a smart phone for a mobile wireless communication tool and a Beacon for position detection of radiation workers using Blue tooth communication. In this report, the developed wireless dose monitoring of cellular phone is introduced.

  16. Radiation damages in chemical components of organic scintillator detectors

    International Nuclear Information System (INIS)

    Fernandes Neto, Jose Maria

    2003-01-01

    Samples containing PPO (1%, g/ml), diluted in toluene, they were irradiated in a 60 Co irradiator (6.46 kGy/h) at different doses. The PPO concentration decay bi-exponentially with the dose, generating the degradation products: benzoic acid, benzamide and benzilic alcohol. The liquid scintillator system was not sensitive to the radiation damage until 20 kGy. Otherwise, the pulse height analysis showed that dose among 30 to 40 kGy generate significant loss of quality of the sensor (liquid scintillating) and the light yield was reduced in half with the dose of (34.04 ± 0.80) kGy. This value practically was confirmed by the photo peak position analysis that resulted D 1/2 = (31.7 ± 1,4) kGy, The transmittance, at 360 nm, of the irradiated solution decreased exponentially. The compartmental model using five compartments (fast decay PPO, slow decay PPO, benzamide, benzoic acid and benzilic alcohol) it was satisfactory to explain the decay of the PPO in its degradation products in function of the dose. The explanation coefficient r 2 = 0.985636 assures that the model was capable to explain 98.6% of the experimental variations. The Target Theory together with the Compartmental Analysis showed that PPO irradiated in toluene solution presents two sensitive molecular diameters both of them larger than the true PPO diameter. >From this analysis it showed that the radiolytic are generated, comparatively, at four toluene molecules diameter far from PPO molecules. For each one PPO-target it was calculated the G parameter (damage/100 eV). For the target expressed by the fast decay the G value was (418.4 ± 54.1) damages/100 eV, and for the slow decay target the G value was (54.5 ± 8.9) damages/100 eV. The energies involved in the chemical reactions were w (0.239 ± 0.031) eV/damage (fast decay) and w = (1 834 ± 0.301) eV/damage (slow decay). (author)

  17. SLC energy spectrum monitor using synchrotron radiation

    International Nuclear Information System (INIS)

    Seeman, J.; Brunk, W.; Early, R.; Ross, M.; Tillmann, E.; Walz, D.

    1986-01-01

    The SLAC linac is being upgraded for the use in the SLAC Linear Collider (SLC). The improved linac must accelerate electron and positron bunches from 1.2 GeV to 50 GeV while producing output energy spectra of about 0.2%. The energy spectra must be maintained during operation to provide for good beam transmission and to minimize chromatic effects in the SLC ARCs and Final Focus. The energy spectra of these beams are determined by the bunch length and intensity, the RF phase and waveform and the intra-bunch longitudinal wakefields. A non-destructive energy spectrum monitor has been designed using a vertical wiggler magnet located downstream of the horizontal beam splitter at the end of the SLC linac. It produces synchrotron radiation which is viewed in an off-axis x-ray position sensitive detector. The expected resolution is 0.08 %. The design considerations of this monitor are presented. A pair of these monitors is under construction with an installation data set for late summer 1986

  18. SLC energy spectrum monitor using synchrotron radiation

    International Nuclear Information System (INIS)

    Seeman, J.; Brunk, W.; Early, R.; Ross, M.; Tillmann, E.; Walz, D.

    1986-04-01

    The SLAC Linac is being upgraded for the use in the SLAC Linear Collider (SLC). The improved Linac must accelerate electron and positron bunches from 1.2 GeV to 50 GeV while producing output energy spectra of about 0.2%. The energy spectra must be maintained during operation to provide for good beam transmission and to minimize chromatic effects in the SLC ARCs and Final Focus. the energy spectra of these beams are determined by the bunch length and intensity, the RF phase and waveform and the intra-bunch longitudinal wakefields. A non-destructive energy spectrum monitor has been designed using a vertical wiggler magnet located downstream of the horizontal beam splitter at the end of the SLC Linac. It produces synchrotron radiation which is viewed in an off-axis x-ray position sensitive detector. The expected resolution is 0.08%. The design considerations of this monitor are presented in this paper. A pair of these monitors is under construction with an installation date set for late summer 1986. 5 refs., 6 figs

  19. Chemical implications of heat and radiation damage to rock salt

    International Nuclear Information System (INIS)

    Pederson, L.R.

    1984-11-01

    Chemical changes induced in Palo Duro and Paradox Basin natural rock salts and in synthetic NaCl by heat and gamma radiation were investigated. Heating of unirradiated natural rock salts to 300 0 C resulted in HCl (most prevalent), SO 2 , CO 2 , and H 2 S evolution, and increased the base content of the remaining salt by not more than 10 microequivalents per gram; whereas, heating of synthetic NaCl gave no product. Gamma irradiation produced sodium colloids and neutral chlorine in amounts similar to the results of Levy and coworkers. When the irradiated salts were heated, three reactions were apparent: (1) radiation-induced defects recombined; (2) neutral chlorine was evolved; and (3) HCl, SO 2 , CO 2 , and H 2 S were evolved, similar to results for unirradiated salts. Because reaction (1) appeared to dominate over reaction (2), it is expected that the influence of radiation damage to salt on the near-field chemical environment will be minor. 4 figures, 1 table

  20. Mitigating radiation damage of single photon detectors for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Anisimova, Elena; Higgins, Brendon L.; Bourgoin, Jean-Philippe [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Cranmer, Miles [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); Choi, Eric [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); Magellan Aerospace, Ottawa, ON (Canada); Hudson, Danya; Piche, Louis P.; Scott, Alan [Honeywell Aerospace (formerly COM DEV Ltd.), Ottawa, ON (Canada); Makarov, Vadim [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); Jennewein, Thomas [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Canadian Institute for Advanced Research, Quantum Information Science Program, Toronto, ON (Canada)

    2017-12-15

    Single-photon detectors in space must retain useful performance characteristics despite being bombarded with sub-atomic particles. Mitigating the effects of this space radiation is vital to enabling new space applications which require high-fidelity single-photon detection. To this end, we conducted proton radiation tests of various models of avalanche photodiodes (APDs) and one model of photomultiplier tube potentially suitable for satellite-based quantum communications. The samples were irradiated with 106 MeV protons at doses approximately equivalent to lifetimes of 0.6, 6, 12 and 24 months in a low-Earth polar orbit. Although most detection properties were preserved, including efficiency, timing jitter and afterpulsing probability, all APD samples demonstrated significant increases in dark count rate (DCR) due to radiation-induced damage, many orders of magnitude higher than the 200 counts per second (cps) required for ground-to-satellite quantum communications. We then successfully demonstrated the mitigation of this DCR degradation through the use of deep cooling, to as low as -86 C. This achieved DCR below the required 200 cps over the 24 months orbit duration. DCR was further reduced by thermal annealing at temperatures of +50 to +100 C. (orig.)

  1. Computer simulations of radiation damage in protein crystals; Simulationsrechnungen zu Strahlenschaeden an Proteinkristallen

    Energy Technology Data Exchange (ETDEWEB)

    Zehnder, M

    2007-03-15

    The achievable resolution and the quality of the dataset of an intensity data collection for structure analysis of protein crystals with X-rays is limited among other factors by radiation damage. The aim of this work is to obtain a better quantitative understanding of the radiation damage process in proteins. Since radiation damage is unavoidable it was intended to look for the optimum ratio between elastically scattered intensity and radiation damage. Using a Monte Carlo algorithm physical processes after an inelastic photon interaction are studied. The main radiation damage consists of ionizations of the atoms through the electron cascade following any inelastic photon interaction. Results of the method introduced in this investigation and results of an earlier theoretical studies of the influence of Auger-electron transport in diamond are in a good agreement. The dependence of the radiation damage as a function of the energy of the incident photon was studied by computer-aided simulations. The optimum energy range for diffraction experiments on the protein myoglobin is 10-40 keV. Studies of radiation damage as a function of crystal volume and shape revealed that very small plate or rod shaped crystals suffer less damage than crystals formed like a cube with the same volume. Furthermore the influence of a few heavy atoms in the protein molecule on radiation damage was examined. Already two iron atoms in the unit cell of myoglobin increase radiation damage significantly. (orig.)

  2. Increase in Efficiency of Use of Pedestrian Radiation Portal Monitors

    Science.gov (United States)

    Solovev, D. B.; Merkusheva, A. E.

    2017-11-01

    Most international airports in the world use radiation portal monitors (RPM) for primary radiation control organization. During the exploitation pedestrian radiation portal monitors operators (in the Russian Federation it is a special subdivision of customs officials) have certain problems related to the search of an ionizing radiation source causing the alarm signal of a radiation monitor. Radiation portal monitors at standard (factory) settings have to find out the illegal moving of the radioisotopes moved by physical persons passing through a controlled zone and having a steady radiation by the gamma or neutron channel. The problem is that recently the number of the ownerships who underwent treatment or medical diagnostics with the use of radio pharmaceuticals considerably increased, i.e,. ownerships represent such an ionizing radiation source. The operator of the radiation portal monitor has to define very quickly whether the ownership is a violator (takes unsolved radioisotopes illegally) or is just a patient of the clinic who underwent treatment/diagnostics with the use of radio pharmaceuticals. The research showing the radioisotopes which are most often used in the medical purposes are given in article, it is offered to use the new software developed by the authors allowing the operator of the radiation portal monitor to define the location of the ownership which has such ionizing radiation source by the activity of radiation similar to the radiation from radio pharmaceuticals.

  3. Imperfection and radiation damage in protein crystals studied with coherent radiation

    International Nuclear Information System (INIS)

    Nave, Colin; Sutton, Geoff; Evans, Gwyndaf; Owen, Robin; Rau, Christoph; Robinson, Ian; Stuart, David Ian

    2016-01-01

    Coherent diffraction observations from polyhedra crystals at cryotemperature are reported. Information is obtained about the lattice strain and the changes with radiation damage. Fringes and speckles occur within diffraction spots when a crystal is illuminated with coherent radiation during X-ray diffraction. The additional information in these features provides insight into the imperfections in the crystal at the sub-micrometre scale. In addition, these features can provide more accurate intensity measurements (e.g. by model-based profile fitting), detwinning (by distinguishing the various components), phasing (by exploiting sampling of the molecular transform) and refinement (by distinguishing regions with different unit-cell parameters). In order to exploit these potential benefits, the features due to coherent diffraction have to be recorded and any change due to radiation damage properly modelled. Initial results from recording coherent diffraction at cryotemperatures from polyhedrin crystals of approximately 2 µm in size are described. These measurements allowed information about the type of crystal imperfections to be obtained at the sub-micrometre level, together with the changes due to radiation damage

  4. Imperfection and radiation damage in protein crystals studied with coherent radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nave, Colin, E-mail: colin.nave@diamond.ac.uk [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom); Sutton, Geoff [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Evans, Gwyndaf; Owen, Robin; Rau, Christoph [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom); Robinson, Ian [University College London, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Stuart, David Ian [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom)

    2016-01-01

    Coherent diffraction observations from polyhedra crystals at cryotemperature are reported. Information is obtained about the lattice strain and the changes with radiation damage. Fringes and speckles occur within diffraction spots when a crystal is illuminated with coherent radiation during X-ray diffraction. The additional information in these features provides insight into the imperfections in the crystal at the sub-micrometre scale. In addition, these features can provide more accurate intensity measurements (e.g. by model-based profile fitting), detwinning (by distinguishing the various components), phasing (by exploiting sampling of the molecular transform) and refinement (by distinguishing regions with different unit-cell parameters). In order to exploit these potential benefits, the features due to coherent diffraction have to be recorded and any change due to radiation damage properly modelled. Initial results from recording coherent diffraction at cryotemperatures from polyhedrin crystals of approximately 2 µm in size are described. These measurements allowed information about the type of crystal imperfections to be obtained at the sub-micrometre level, together with the changes due to radiation damage.

  5. Radiation environmental real-time monitoring and dispersion modelling

    International Nuclear Information System (INIS)

    Kovacik, Andrej; Bartokova, Ivana; Melicherova, Terezia; Omelka, Jozef

    2015-01-01

    The MicroStep-MIS system of real-time radiation monitoring, which provides a turn-key solution for measurement, acquisition, processing, reporting, archiving and displaying of various radiation data, is described and discussed in detail. The qualities, long-term stability of measurement and sensitivity of the RPSG-05 probe are illustrated on its use within the radiation monitoring network of the Slovak Hydrometeorological Institute and within the monitoring network in the United Arab Emirates. (orig.)

  6. Environmental radiation monitoring system with GPS (global positioning system)

    International Nuclear Information System (INIS)

    Komoto, Itsuro

    2000-01-01

    This system combines a radiation monitoring car with GPS and a data processor (personal computer). It distributes the position information acquired through GPS to the data such as measured environmental radiation dose rate and energy spectrum. It also displays and edits the data for each measuring position on a map. Transmitting the data to the power station through mobile phone enables plan managers to easily monitor the environmental radiation dose rate nearby and proper emergency monitoring. (author)

  7. Collision density approach of radiation damage in a multispecies medium

    International Nuclear Information System (INIS)

    Lux, I.; Pazsit, I.

    1981-01-01

    Space-energy dependent forward type equations for the collision densities of energetic atoms in a multispecies semi-infinite homogeneous medium are formulated. Introduction of the one-dimensional isotropic forward-backward model of Fermi for the scattering and application of the Laplace transform with respect to the lethargy variable will lead to a linear differential equation system with constant coefficients. This equation system is solved for an arbitrary number of species and relations between the collision densities and defect distributions of the different species are given in the Kinchin-Pease model of radiation damage. The case of an alien particle incident on a two-component target is examined in some detail and the sputtering spectra for the three species are given numerically. (author)

  8. Radiation damage in amorphous solids - a computer simulation

    International Nuclear Information System (INIS)

    Chaki, T.K.; Li, J.C.M.

    1984-01-01

    It is known for crystalline materials that injection of high energy atoms introduces point defects. The nature of defects is not known for amorphous solids. So a molecular dynamic simulation of radiation damage in an amorphous metal was carried out. An amorphous structure of 685 atoms with periodic boundary conditions in all 3 dimensions was equilibrated first. Then one atom on the surface was given a high initial velocity so it was injected inward. Radial temperature distribution around the line of injection was calculated as a function of time. Void distribution and its evolution with time in the direction of injection was calculated by counting the atomic centers in thin slabs perpendicular to the line of injection. The swelling of the whole solid was calculated also. Some results are compared with experiments

  9. Radiation diagnosis of pelvic ring damages in acute injury

    International Nuclear Information System (INIS)

    Dytalov, M.M.

    2000-01-01

    Data on 58 victims with multifocal damages to the pelvic ring were used to examine the diagnostic potentialities of different radiation diagnostic techniques and to compare their resolving power. The later was 65.1, 83.3 and 94.7% in plain and multidimensional X-ray studies, and computed tomography, respectively. Complex of signs is described closed sacral fractures on the plain and oblique pelvic inlet (caudal) radiograms proposed, which could improve the diagnosis of fractures by 8.8 times, and an original orthopedic gauze-plate for the detection and estimation of invisible pelvic bone displacement, and an original procedure for pelvic X-ray study with target load in acute injury. This all can improve the quality of examination of casualties substantially and define indications for different treatments more precise [ru

  10. Sensitization of ultraviolet radiation damage in bacteria and mammalian cells

    International Nuclear Information System (INIS)

    Fisher, G.J.; Watts, M.E.; Patel, K.B.; Adams, G.E.

    1978-01-01

    Bacteria (Serratia marcescens) and mammalian cells (Chinese hamsters V79-379A) were irradiated in monolayers with ultraviolet light at 254 nm or 365 nm in the presence or absence of radiosensitizing drugs. At 254 nm, killing is very efficient (Dsub(37) approximately equal 1 J m -2 exposure, or approximately equal 6 x 10 4 photons absorbed by DNA per bacterium), and sensitizers have no effect. At 365 nm, cells are not killed in buffer, but are inactivated in the presence of nifurpipone or misonidazole. Lethal exposures (approximately equal 5 x 10 3 J m -2 at 10 nM misonidazole) correspond to about 10 7 photons absorbed by sensitizer molecules per bacterium. Toxicity of stable photoproducts of the drugs is not involved, nor is oxygen required. Hence the transient species formed by photo-excitation of radiosensitizer molecules are capable of killing cells in the absence of other types of radiation damage. (author)

  11. Collision density approach of radiation damage in a multispecies medium

    Energy Technology Data Exchange (ETDEWEB)

    Lux, I; Pazsit, I [Koezponti Elelmiszeripari Kutato Intezet, Budapest (Hungary)

    1981-01-01

    Space-energy dependent forward type equations for the collision densities of energetic atoms in a multispecies semi-infinite homogeneous medium are formulated. Introduction of the one-dimensional isotropic forward-backward model of Fermi for the scattering and application of the Laplace transform with respect to the lethargy variable will lead to a linear differential equation system with constant coefficients. This equation system is solved for an arbitrary number of species and relations between the collision densities and defect distributions of the different species are given in the Kinchin-Pease model of radiation damage. The case of an alien particle incident on a two-component target is examined in some detail and the sputtering spectra for the three species are given numerically.

  12. Radiation Monitoring - A Key Element in a Nuclear Power Program

    International Nuclear Information System (INIS)

    Hussein, A.S.; El-dally, T.A.

    2008-01-01

    For a nuclear power plant, radiation is especially of great concern to the public and the environment. Therefore, a radiation monitoring program is becoming a critical importance. This program covers all phases of the nuclear plant including preoperational, normal operation, accident and decommissioning. The fundamental objective of radiation monitoring program is to ensure that the health and safety of public inside and around the plant and to confirm the radiation doses are below the dose limits for workers and the public. This paper summarizes the environmental radiation monitoring program for a nuclear power plant

  13. Radiation Monitoring System in Advanced Spent Fuel Conditioning Process Facility

    Energy Technology Data Exchange (ETDEWEB)

    You, Gil Sung; Kook, D. H.; Choung, W. M.; Ku, J. H.; Cho, I. J.; You, G. S.; Kwon, K. C.; Lee, W. K.; Lee, E. P

    2006-09-15

    The Advanced spent fuel Conditioning Process is under development for effective management of spent fuel by converting UO{sub 2} into U-metal. For demonstration of this process, {alpha}-{gamma} type new hot cell was built in the IMEF basement . To secure against radiation hazard, this facility needs radiation monitoring system which will observe the entire operating area before the hot cell and service area at back of it. This system consists of 7 parts; Area Monitor for {gamma}-ray, Room Air Monitor for particulate and iodine in both area, Hot cell Monitor for hot cell inside high radiation and rear door interlock, Duct Monitor for particulate of outlet ventilation, Iodine Monitor for iodine of outlet duct, CCTV for watching workers and material movement, Server for management of whole monitoring system. After installation and test of this, radiation monitoring system will be expected to assist the successful ACP demonstration.

  14. RadNet (Environmental Radiation Ambient Monitoring System)

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet, formerly Environmental Radiation Ambient Monitoring System (ERAMS), is a national network of monitoring stations that regularly collect air, precipitation,...

  15. Radiation Monitoring System in Advanced Spent Fuel Conditioning Process Facility

    International Nuclear Information System (INIS)

    You, Gil Sung; Kook, D. H.; Choung, W. M.; Ku, J. H.; Cho, I. J.; You, G. S.; Kwon, K. C.; Lee, W. K.; Lee, E. P.

    2006-09-01

    The Advanced spent fuel Conditioning Process is under development for effective management of spent fuel by converting UO 2 into U-metal. For demonstration of this process, α-γ type new hot cell was built in the IMEF basement . To secure against radiation hazard, this facility needs radiation monitoring system which will observe the entire operating area before the hot cell and service area at back of it. This system consists of 7 parts; Area Monitor for γ-ray, Room Air Monitor for particulate and iodine in both area, Hot cell Monitor for hot cell inside high radiation and rear door interlock, Duct Monitor for particulate of outlet ventilation, Iodine Monitor for iodine of outlet duct, CCTV for watching workers and material movement, Server for management of whole monitoring system. After installation and test of this, radiation monitoring system will be expected to assist the successful ACP demonstration

  16. Involvement of membrane lipids in radiation damage to potassium-ion permeability of Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S [Tokyo Univ. (Japan). Inst. for Medical Science; Akamatsu, Y

    1978-02-01

    Radiation damage to K/sup +/ permeability of an unsaturated fatty acid auxotroph of E.coli grown with oleate or linolenate was investigated at different temperatures. A remarkable effect of radiation was observed at 0/sup 0/C with cells that had been grown in linolenate at 42/sup 0/C. This indicates that, besides protein, membrane lipids at least are involved in the radiation damage. The damage also seems to be affected by the fluidity of membrane lipids.

  17. Ultraviolet radiation-mediated damage to cellular DNA

    International Nuclear Information System (INIS)

    Cadet, Jean; Sage, Evelyne; Douki, Thierry

    2005-01-01

    Emphasis is placed in this review article on recent aspects of the photochemistry of cellular DNA in which both the UVB and UVA components of solar radiation are implicated individually or synergistically. Interestingly, further mechanistic insights into the UV-induced formation of DNA photoproducts were gained from the application of new accurate and sensitive chromatographic and enzymic assays aimed at measuring base damage. Thus, each of the twelve possible dimeric photoproducts that are produced at the four main bipyrimidine sites can now be singled out as dinucleoside monophosphates that are enzymatically released from UV-irradiated DNA. This was achieved using a recently developed high-performance liquid chromatography-tandem mass spectrometry assay (HPLC-MS/MS) assay after DNA extraction and appropriate enzymic digestion. Interestingly, a similar photoproduct distribution pattern is observed in both isolated and cellular DNA upon exposure to low doses of either UVC or UVB radiation. This applies more specifically to the DNA of rodent and human cells, the cis-syn cyclobutadithymine being predominant over the two other main photolesions, namely thymine-cytosine pyrimidine (6-4) pyrimidone adduct and the related cyclobutyl dimer. UVA-irradiation was found to generate cyclobutane dimers at TT and to a lower extent at TC sites as a likely result of energy transfer mechanism involving still unknown photoexcited chromophore(s). Oxidative damage to DNA is also induced although less efficiently by UVA-mediated photosensitization processes that mostly involved 1 O 2 together with a smaller contribution of hydroxyl radical-mediated reactions through initially generated superoxide radicals

  18. Micronuclei: sensitivity for the detection of radiation induced damage

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Nasazzi, N.B.; Taja, M.R.

    1998-01-01

    The in vitro cytokinesis-block (CB) micronucleus (MN) assay for human peripheral blood has been used extensively for the assessment of chromosomal damage induced by ionizing radiation and chemicals and considered a suitable biological dosimeter for estimating in vivo whole body exposures, particularly in the case of large scale radiation accidents. One of the major drawbacks of the MN assay is its reduced sensitivity for the detection of damage induced by low doses of low LET radiation, due to the high variability among the spontaneous MN frequencies. It is suggested that age, smoking habit and sex are the main confounding factors that contribute to the observed variability. Previous work in our laboratory, shows a significant positive correlation of the spontaneous and radiation induced MN frequencies with age and smoking habit, the latter being the strongest confounder. These findings led to in vitro studies of the dose-response relationships for smoking and non smoking donors evaluated separately, using 60 Co γ rays. The objectives of the present work are: 1-To increase the amount of data of the dose-response relationships, using γ rays from a 60 Co source, for smoking and non smoking donors, in order to find, if applicable, a correction factor for the calibration curve that takes into account the smoking habit of the individual in the case of accidental overexposure dose assessment, particularly in the low dose range. 2-To establish general conclusions on the current state of the technique. The sample for smoking and non smoking calibration curves was enlarged in the range of 0Gy to 2Gy. The fitting of both curves, performed up to the 2Gy dose, resulted in a linear quadratic model. MN distribution among bi nucleated cells was found to be over dispersed with respect to Poisson distribution, the average ratio of variance to mean being 1.13 for non smokers and 1.17 for smokers. Each fitted calibration curve, for smoking and non smoking donors, fell within the 95

  19. Dislocations and radiation damage in α-uranium

    International Nuclear Information System (INIS)

    Leteurtre, J.

    1969-01-01

    Dislocations in α-uranium were studied by electron microscopy. Electropolishing of thin foils was performed at low temperature (-110 deg. C) to prevent oxidation. Burgers vectors of twins dislocations are defined. Interactions between slip and twinning are studied from both experimental and theoretical point of view. Samples irradiated at several burn-up were examined. In order to explain our micrographic results, and also all information gathered in literature about radiation damage in α-uranium, a coherent model is propound for the fission particles effects. We analyse the influences of parameters: temperature, dislocation density, impurity content. The number of point defects created by one initial fission is determined for pure and annealed metal. The importance of the self-anneal which occurs immediately in each displacement spike, and the anneal due to a new fission on the damage resulting from a previous fission, are estimated. The focussing distance in [100] direction is found to be about 1000 Angstrom, at 4 deg. K. (author) [fr

  20. Long term radiological features of radiation-induced lung damage.

    Science.gov (United States)

    Veiga, Catarina; Landau, David; McClelland, Jamie R; Ledermann, Jonathan A; Hawkes, David; Janes, Sam M; Devaraj, Anand

    2018-02-01

    To describe the radiological findings of radiation-induced lung damage (RILD) present on CT imaging of lung cancer patients 12 months after radical chemoradiation. Baseline and 12-month CT scans of 33 patients were reviewed from a phase I/II clinical trial of isotoxic chemoradiation (IDEAL CRT). CT findings were scored in three categories derived from eleven sub-categories: (1) parenchymal change, defined as the presence of consolidation, ground-glass opacities (GGOs), traction bronchiectasis and/or reticulation; (2) lung volume reduction, identified through reduction in lung height and/or distortions in fissures, diaphragm, anterior junction line and major airways anatomy, and (3) pleural changes, either thickening and/or effusion. Six patients were excluded from the analysis due to anatomical changes caused by partial lung collapse and abscess. All remaining 27 patients had radiological evidence of lung damage. The three categories, parenchymal change, shrinkage and pleural change were present in 100%, 96% and 82% respectively. All patients had at least two categories of change present and 72% all three. GGOs, reticulation and traction bronchiectasis were present in 44%, 52% and 37% of patients. Parenchymal change, lung shrinkage and pleural change are present in a high proportion of patients and are frequently identified in RILD. GGOs, reticulation and traction bronchiectasis are common at 12 months but not diagnostic. Copyright © 2017 Elsevier B.V. All rights reserved.