Radiation effects on power cables for nuclear power plants

International Nuclear Information System (INIS)

Arora, R.; Munshi, P.; Badshah, M.G.Q.

1988-01-01

A large number of power and control cables, insulated with organic/polymeric materials, are installed quite near the reactor in nuclear power plants. The reliability of electrical equipment, receiving power through these cables, is critically important for the design and safety of the power stations. The radiation intensity inside the containment varies significantly from one location to another. The extent of material degradation is associated with the local radiation intensity. The cables used in the nuclear environment require several unique properties, the most obvious of these being radiation resistance, fire resistance, and the ability to withstand the loss-of-coolant accident in a nuclear power plant as specified in Institute of Electrical and Electronics Engineers (IEEE) Standard 383. In this study, four specific electrical power cable samples insulated with polyethylene, polyvinyl chloride, ethylene propylene rubber, and silicone rubber were chosen to investigate the effect of radiation in reactor environments on the electrical properties of the samples. Voltage breakdown tests and dielectric loss factor (tan δ) and conductor resistance measurements were carried out on each sample before and after irradiating them to near lifetime doses at ambient temperatures in atmospheric conditions

Multi-gigabit low-power radiation-tolerant data links and improved data motion in trackers

International Nuclear Information System (INIS)

Miller, M; Brewer, F; Wang, D; Magazzu, G

2014-01-01

We present a set of links based on data-transmission IP in 130nm designed for rapid integration into ASIC designs. These links are designed for use in very high radiation environments as occur in high energy physics experiments. The designs are additionally low power and small area, easing integration with other electronic systems. These links are well suited to use in tracking detectors. Trackers, due to their close proximity to the collision, are subject to very high levels of radiation, and hence require such radiation hardened electronics. The portfolio of radiation hardened data transmission blocks consists of a 1Gbps serializer/deserializer with a very low power consumption ∼ 1mW for each. A differential transmitter and differential receiver rated at 3GHz, both designed to be much faster than needed, as insurance against radiation damage. Finally, the impact of a prototype low-latency, low-power ( < 60mW total link power) 5Gbps link is considered. Case analysis of the impacts of using lower powered, higher speed blocks in hypothetical trackers is studied, showing power improvements relative to alternative technologies

Estimated population exposure from nuclear power production and other radiation sources

International Nuclear Information System (INIS)

Pochin, E.E.

1976-01-01

Estimates are given of the total radiation dose from all forms of ionizing radiation resulting from nuclear power reduction. A power consumption of 1kW per head of population, derived entirely from nuclear energy, would increase the average radiation exposure of the whole population from 100mrem per year from natural sources (plus about 40mrem per year from medical procedures and other artificial causes) by about 6mrem per year. The genetically signifificant component of this increase would be about 4mrem per year. Available estimates of harm from radiation would indicate that this would give a risk per year per million of population of about 1 fatal induced malignancy, about the same number of malignancies fully treatable by operation, and, after many generations, about the same number of inherited defects, of greater or less severity, per year. Accidental injuries, particularly in constructional and mining work, would cause an estimated 1 fatality and 50 other accidents annually. Indications are given of the number of fatalities and accidents involved in equal power production by alternative methods, and of the value and limitations of such numerical comparisons in reaching decisions on the development of future power programmes

Association of Radon Background and Total Background Ionizing Radiation with Alzheimer's Disease Deaths in U.S. States.

Science.gov (United States)

Lehrer, Steven; Rheinstein, Peter H; Rosenzweig, Kenneth E

2017-01-01

Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

The effects of ionizing radiation on commercial power MOSFETs operated at cryogenic temperatures

International Nuclear Information System (INIS)

Johnson, G.H.; Kemp, W.T.; Ackermann, M.R.; Pugh, R.D.; Schrimpf, R.D.; Galloway, K.F.

1994-01-01

This is the first report of commercial n- and p-channel power MOSFETs exposed to ionizing radiation while operating in a cryogenic environment. The transistors were exposed to low energy x-rays while placed in a liquid nitrogen-cooled dewar. Results demonstrate significant performance and survivability advantages for space-borne power MOSFETs operated at cryogenic temperatures. The key advantages for low-temperature operation of power MOSFET's in an ionizing radiation environment are: (1) steeper subthreshold current slope before and after irradiation; (2) lower off-state leakage currents before and after irradiation; and (3) larger prerad threshold voltage for n-channel devices. The first two points are also beneficial for devices that are not irradiated, but the advantages are more significant in radiation environments. The third point is only an advantage for commercial devices operated in radiation environments. Results also demonstrate that commercial off-the-shelf power MOSFETs can be used for low-temperature operations in a limited total dose environment (i.e., many space applications)

Parametric variation of radiated power in Aditya Tokamak

International Nuclear Information System (INIS)

Tahiliani, Kumudni; Chowdhuri, M.B.; Manchanda, R.

2017-01-01

We report the study of parametric variation of radiated power in Aditya Tokamak for ohmic discharges. The radiated power was measured using AXUV diodes that are responsive to radiation in the range 1 eV to 4 keV and are insensitive to the neutral particles (<0.5 keV). Hence only the radiation power loss is measured and charge exchange losses are excluded. The measured radiated power was also used for the estimation of the effective ion charge, Z eff based on the scaling obtained by the regression analysis of the data from multiple Tokamaks. The estimated values were compared with the experimental Z eff values obtained from the visible continuum measurement. We also tested the scaling for modelled radiation power loss. (author)

FEL radiation power available in electron storage rings

International Nuclear Information System (INIS)

Miyahara, Yoshikazu

1994-01-01

FEL radiation power available in electron storage rings was studied in the small signal regime in considering the increase of the energy spread of the electron beam caused by the FEL interaction and the decrease of the FEL gain with the increase of the energy spread in addition to the radiation damping and the quantum excitation. All these effects were considered separately, and combined with FEL power equations. The radiation power available was expressed explicitly with the parameters of the storage ring, the wiggler and the mirrors. The transient process of FEL lasing is simulated with the power equations. A rough estimation is made of the radiation power available by the FEL at different beam energies, and optimization of FEL parameters for a higher radiation power is discussed. ((orig.))

Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target.

Science.gov (United States)

Dubey, P K; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

2014-05-01

The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

Science.gov (United States)

Dubey, P. K.; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

2014-05-01

The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

International Nuclear Information System (INIS)

Dubey, P. K.; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

2014-01-01

The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique

Experimental determination of radiated internal wave power without pressure field data

Science.gov (United States)

Lee, Frank M.; Paoletti, M. S.; Swinney, Harry L.; Morrison, P. J.

2014-04-01

We present a method to determine, using only velocity field data, the time-averaged energy flux left and total radiated power P for two-dimensional internal gravity waves. Both left and P are determined from expressions involving only a scalar function, the stream function ψ. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data.

Experimental determination of radiated internal wave power without pressure field data

International Nuclear Information System (INIS)

Lee, Frank M.; Morrison, P. J.; Paoletti, M. S.; Swinney, Harry L.

2014-01-01

We present a method to determine, using only velocity field data, the time-averaged energy flux (J) and total radiated power P for two-dimensional internal gravity waves. Both (J) and P are determined from expressions involving only a scalar function, the stream function ψ. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data

Radiation tolerant power converter controls

CERN Document Server

Todd, B; King, Q; Uznanski, S

2012-01-01

The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to signifi...

Self-powered radiation detector

International Nuclear Information System (INIS)

Goldstein, N.P.; Todt, W.H.

1979-01-01

Self-powered gamma radiation detector composed of a conducting emitter surrounded by an insulating medium and a conducting tubular collector, the emitter being a hollow tube containing an electrical insulator [fr

Sound radiation quantities arising from a resilient circular radiator

NARCIS (Netherlands)

Aarts, R.M.; Janssen, A.J.E.M.

2009-01-01

Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are

Radiation workers of nuclear power stations and a method of regional economic development

International Nuclear Information System (INIS)

Nakagawa, Haruo

2003-01-01

In Japan, most of the electric power companies depend on radiation works to the external labor, but the employment of radiation works lacks its' stability. From the analysis on the mobility of radiation workers, we can see the stability of employment increases in proportion to the number of reactors. The radiation work is legally classified to harmful in Japan. And many health control systems for radiation workers are applied strictly. If we apply the health records registration system to the health control systems and involve them to the regional health care system, we can get more effective plan for regional economic development. It is therefore, very important to strive for employee controls, radiation controls, health examinations and data control. Furthermore, it is necessary to establish a total data management system that processes numerous amounts of data concerning radiation employees. This paper proposes the need for such a registration system to set up the system within regional medical information systems, and proposes the establishment of a radiation work market on the web using a total data management system. The system will include radiation employee control information service for members who are planning new employment contracts. (author)

Environmental radiation monitoring system in nuclear power station

International Nuclear Information System (INIS)

Matsuoka, Sadazumi; Tadachi, Katsuo; Endo, Mamoru; Yuya, Hiroshi

1983-01-01

At the time of the construction of nuclear power stations, prior to their start of operation, the state of environmental radiation must be grasped. After the start of the power stations, based on those data, the system of environmental radiation monitoring is established. Along with the construction of Kashiwazaki-Kariwa Nuclear Power Station, The Tokyo Electric Power Co., Inc. jointly with Fujitsu Ltd. has developed a high-reliability, environmental radiation monitoring system, and adopted ''optical data highways'' using optical fiber cables for communication. It consists of a central monitoring station and 11 telemeter observation points, for collecting both radiation and meteorological data. The data sent to the central station through the highways are then outputted on a monitoring panel. They are analyzed with a central processor, and the results are printed out. (Mori, K.)

Radiation resistance of wide-bandgap semiconductor power transistors

Energy Technology Data Exchange (ETDEWEB)

Hazdra, Pavel; Popelka, Stanislav [Department of Microelectronics, Czech Technical University in Prague (Czech Republic)

2017-04-15

Radiation resistance of state-of-the-art commercial wide-bandgap power transistors, 1700 V 4H-SiC power MOSFETs and 200 V GaN HEMTs, to the total ionization dose was investigated. Transistors were irradiated with 4.5 MeV electrons with doses up to 2000 kGy. Electrical characteristics and introduced defects were characterized by current-voltage (I-V), capacitance-voltage (C-V), and deep level transient spectroscopy (DLTS) measurements. Results show that already low doses of 4.5 MeV electrons (>1 kGy) cause a significant decrease in threshold voltage of SiC MOSFETs due to embedding of the positive charge into the gate oxide. On the other hand, other parameters like the ON-state resistance are nearly unchanged up to the dose of 20 kGy. At 200 kGy, the threshold voltage returns back close to its original value, however, the ON-state resistance increases and transconductance is lowered. This effect is caused by radiation defects introduced into the low-doped drift region which decrease electron concentration and mobility. GaN HEMTs exhibit significantly higher radiation resistance. They keep within the datasheet specification up to doses of 2000 kGy. Absence of dielectric layer beneath the gate and high concentration of carriers in the two dimensional electron gas channel are the reasons of higher radiation resistance of GaN HEMTs. Their degradation then occurs at much higher doses due to electron mobility degradation. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Ionizing radiation risks to Satellite Power Systems (SPS) workers in space

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

A reference Satellite Power System (SPS) has been designed by NASA and its contractors for the purposes of evaluating the concept and carrying out assessments of the various consequences of development, including those on the health of the space workers. The Department of Energy has responsibility for directing various assessments. Present planning calls for the SPS workers to move from Earth to a low earth orbit (LEO) at an altitude of 500 kilometers; to travel by a transfer ellipse (TE) trajectory to a geosynchronous orbit (GEO) at an altitude of 36,000 kilometers; and to remain in GEO orbit for about 90 percent of the total time aloft. The radiation risks to the health of workers who will construct and maintain solar power satellites in the space environment are studied. The charge to the committee was: (a) to evaluate the radiation environment estimated for the Reference System which could represent a hazard; (b) to assess the possible somatic and genetic radiation hazards; and (c) to estimate the risks to the health of SPS workers due to space radiation exposure, and to make recommendations based on these conclusions. Details are presented. (WHK)

Environmental radiation exposure in case of power plant accidents

International Nuclear Information System (INIS)

Eder, K.

1977-01-01

The paper tries to overcome prejudices concerning radiation effects due to power plant accidents as well as to show the radiation exposure that may be expected near the the patient and to indicate ways and means to avoid or reduce this radiation exposure and to avoid contamination. It is a contribution to better information on radiation accidents and radiolesions in nuclear power plants with the aim of close cooperation between power plants, physicians, and hospitals and of helping to overcome erroneous popular assumptions. (orig./HP) [de

Impact of Total Ionizing Dose Radiation Testing and Long-Term Thermal Cycling on the Operation of CMF20120D Silicon Carbide Power MOSFET

Science.gov (United States)

Patterson, Richard L.; Scheidegger, Robert J.; Lauenstein, Jean-Marie; Casey, Megan; Scheick, Leif; Hammoud, Ahmad

2013-01-01

Power systems designed for use in NASA space missions are required to work reliably under harsh conditions including radiation, thermal cycling, and extreme temperature exposures. Silicon carbide devices show great promise for use in future power electronics systems, but information pertaining to performance of the devices in the space environment is very scarce. A silicon carbide N-channel enhancement-mode power MOSFET called the CMF20120 is of interest for use in space environments. Samples of the device were exposed to radiation followed by long-term thermal cycling to address their reliability for use in space applications. The results of the experimental work are presentd and discussed.

Nuclear Power and Radiation in Public Acceptance

International Nuclear Information System (INIS)

Vastchenko, S. V.

2002-01-01

The special knowledge deficiency does not give the possibility to the majority of people to pattern their behaviour in a correct way on radiation problems and to estimate faithfully the possible damage rate to the health of a human being from the different radiation sources effects. Studying of the public opinion in Belarus has shown that one of the results of the Chernobyl NPP accident consequences is inseparability of nuclear and radiation danger in public consciousness. The anonymous questionnaire of the inhabitants living in various Belarus regions has been carried out aiming at definition of a general radiation erudition, as well as revealing the knowledge of the population about the effect of power stations (nuclear and thermal) on the environment and the human being health. Answers on questions connected with power have shown a very poor erudition of population about ecological advantages and drawbacks inherent in thermal and nuclear power plants. The majority of the respondents (about 80%) does not know about the absence of CO 2 discharge and oxygen preservation in the air. The questionnaire analysis shows that people are exclusively frightened with radiation from NPPs, but the rest sources of radiation effect do not cause so anxiety and apprehension. People in Belarus have learnt well that the reason of the majority of the diseases is radiation, so it can be frequently heard not only from mass media, but also at scientific conferences and seminars. Most of medical workers are sure that all diseases are caused by radiation. The deficiency of special knowledge on nuclear technologies in the people majority and availability of a great amount of contradictory and untrue information supplied by mass media result in overestimation of danger from energy objects and underestimation of the increased radiation dose from other sources consequences, for example, under roentgen medical examination and treatment. The investigations carried out will help to arrange

High-resolution Tangential AXUV Arrays for Radiated Power Density Measurements on NSTX-U

Energy Technology Data Exchange (ETDEWEB)

Delgado-Aparicio, L [PPPL; Bell, R E [PPPL; Faust, I [MIT; Tritz, K [The Johns Hopkins University, Baltimore, MD, 21209, USA; Diallo, A [PPPL; Gerhardt, S P [PPPL; Kozub, T A [PPPL; LeBlanc, B P [PPPL; Stratton, B C [PPPL

2014-07-01

Precise measurements of the local radiated power density and total radiated power are a matter of the uttermost importance for understanding the onset of impurity-induced instabilities and the study of particle and heat transport. Accounting of power balance is also needed for the understanding the physics of various divertor con gurations for present and future high-power fusion devices. Poloidal asymmetries in the impurity density can result from high Mach numbers and can impact the assessment of their flux-surface-average and hence vary the estimates of P[sub]rad (r, t) and (Z[sub]eff); the latter is used in the calculation of the neoclassical conductivity and the interpretation of non-inductive and inductive current fractions. To this end, the bolometric diagnostic in NSTX-U will be upgraded, enhancing the midplane coverage and radial resolution with two tangential views, and adding a new set of poloidally-viewing arrays to measure the 2D radiation distribution. These systems are designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate non-inductive operation at reduced collisionality, with high-pressure, long energy-confinement-times and a divertor solution with metal walls.

Personnel radiation safety in nuclear power plants

International Nuclear Information System (INIS)

Elkert, J.

1979-05-01

The principal contributions to the radiation doses of the Swedish power reactor personnel are identified. The possi bilities to reduce these doses are examined. The radiation doses are analyzed according to different personnel categories, specific maintenance operations or inspections and to different radiation activities. Suggestions are given for reducing the radiation doses. (L.E.)

Radiation streaming in power reactors. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Lahti, G.P.; Lee, R.R.; Courtney, J.C. (eds.)

1979-02-01

Separate abstracts are included for each of the 14 papers given at a special session on Radiation Streaming in Power Reactors held on November 15 at the American Nuclear Society 1978 Winter Meeting in Washington, D.C. The papers describe the methods of calculation, the engineering of shields, and the measurement of radiation environments within the containments of light water power reactors. Comparisons of measured and calculated data are used to determine the accuracy of computer predictions of the radiation environment. Specific computational and measurement techniques are described and evaluated. Emphasis is on radiation streaming in the annular region between the reactor vesel and the primary shield and its resultant environment within the primary containment.

Development of lightweight radiators for lunar based power systems

International Nuclear Information System (INIS)

Juhasz, A.J.; Bloomfield, H.S.

1994-05-01

This report discusses application of a new lightweight carbon-carbon (C-C) space radiator technology developed under the NASA Civil-Space Technology Initiative (CSTI) High Capacity Power Program to a 20 kWe lunar based power system. This system comprises a nuclear (SP-100 derivative) heat source, a Closed Brayton Cycle (CBC) power conversion unit with heat rejection by means of a plane radiator. The new radiator concept is based on a C-C composite heat pipe with integrally woven fins and a thin walled metallic liner for containment of the working fluid. Using measured areal specific mass values (1.5 kg/m2) for flat plate radiators, comparative CBC power system mass and performance calculations show significant advantages if conventional heat pipes for space radiators are replaced by the new C-C heat pipe technology

Compact high-power terahertz radiation source

Directory of Open Access Journals (Sweden)

G. A. Krafft

2004-06-01

Full Text Available In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator on the return leg, is discussed. Because the beam is recirculated and not stored, short bunches may be produced that radiate coherently in the undulator, yielding exceptionally high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes, limits the charge-per-bunch possible in such a device.

47 CFR 22.913 - Effective radiated power limits.

Science.gov (United States)

2010-10-01

... radiated power (ERP) of transmitters in the Cellular Radiotelephone Service must not exceed the limits in this section. (a) Maximum ERP. In general, the effective radiated power (ERP) of base transmitters and... areas, as those areas are defined in § 22.949, the ERP of base transmitters and cellular repeaters of...

A new career path in radiation protection training. Certified power plant shift supervisor. Radiation protection

International Nuclear Information System (INIS)

Terbeek, Christoph

2011-01-01

Apart from theoretical knowledge, effective day-to-day radiation protection operations also require a certain measure of practical experience. Therefore, the professional degree of 'Certified Radiation Worker', issued by the Chamber of Industry and Commerce (CIC) Aachen, Germany, established at an early stage. In order to provide experienced radiation protection specialists with an attractive career path, POWERTECH TRAINING CENTER e.V., in co-operation with VGB PowerTech. e.V., the Paul Scherrer Institute (Switzerland) and the Swiss Atomic Energy Agency (ENSI), has devised a new power plant shift supervisor training course specialising in radiation protection. The vocational training degree called 'Certified Power Plant Shift Supervisor - Radiation Protection' is awarded after successful completion of the advanced training examination conducted by the CIC in Essen, Germany. (orig.)

Radiating properties of solar plasmas

Science.gov (United States)

Bruner, M. E.; Mcwhirter, R. W. P.

1988-01-01

Using a series of 14 previously obtained empirical emission measure distributions and a number of spectral lines observed by the SMM and P78-1 instruments, the total power radiated by a hot plasma is compared to that radiated by individual spectrum lines. Results are presented for different choices of ionization balance and power loss functions. The results indicate that for some lines such as the C IV resonance doublet at 1548 A and 1550 A, the ratio of the line intensity to the total radiated power varied only over a factor of 2, suggesting that well-calibrated measurements of a single line intensity may provide a fairly good estimation of the total radiated power output from the solar plasma.

Radiating properties of solar plasmas

International Nuclear Information System (INIS)

Bruner, M.E.; Mcwhirter, R.W.P.

1988-01-01

Using a series of 14 previously obtained empirical emission measure distributions and a number of spectral lines observed by the SMM and P78-1 instruments, the total power radiated by a hot plasma is compared to that radiated by individual spectrum lines. Results are presented for different choices of ionization balance and power loss functions. The results indicate that for some lines such as the C IV resonance doublet at 1548 A and 1550 A, the ratio of the line intensity to the total radiated power varied only over a factor of 2, suggesting that well-calibrated measurements of a single line intensity may provide a fairly good estimation of the total radiated power output from the solar plasma. 21 references

Measurement of the energy and power radiated by a pulsed blackbody x-ray source

International Nuclear Information System (INIS)

Chandler, Gordon Andrew; McDaniel, Dillon Heirman; Jorgenson, Roy E.; Warne, Larry Kevin; Dropinski, Steven Clark; Hanson, Donald L.; Johnson, William Arthur; York, Mathew William; Lewis, D.F.; Korde, R.; Haslett, C.L.; Wall, D.L.; Ruggles, Laurence E.; Ramirez, L.E.; Stygar, William A.; Porter, John Larry Jr.; McKenney, John Lee; Bryce, Edwin Anthony; Cuneo, Michael Edward; Torres, Jose A.; Mills, Jerry Alan; Leeper, Ramon Joe; McGurn, John Stephen; Fehl, David Lee; Spielman, R. B.; Pyle, John H.; Mazarakis, Michael Gerrassimos; Ives III, Harry Crockett; Seamen, Johann F.; Simpson, Walter W.

2006-01-01

We have developed a diagnostic system that measures the spectrally integrated (i.e. the total) energy and power radiated by a pulsed blackbody x-ray source. The total-energy-and-power (TEP) diagnostic system is optimized for blackbody temperatures between 50 and 350 eV. The system can view apertured sources that radiate energies and powers as high as 2 MJ and 200 TW, respectively, and has been successfully tested at 0.84 MJ and 73 TW on the Z pulsed-power accelerator. The TEP system consists of two pinhole arrays, two silicon-diode detectors, and two thin-film nickel bolometers. Each of the two pinhole arrays is paired with a single silicon diode. Each array consists of a 38 x 38 square array of 10-(micro)m-diameter pinholes in a 50-(micro)m-thick tantalum plate. The arrays achromatically attenuate the x-ray flux by a factor of ∼1800. The use of such arrays for the attenuation of soft x rays was first proposed by Turner and co-workers [Rev. Sci. Instrum. 70, 656 (1999)RSINAK0034-674810.1063/1.1149385]. The attenuated flux from each array illuminates its associated diode; the diode's output current is recorded by a data-acquisition system with 0.6-ns time resolution. The arrays and diodes are located 19 and 24 m from the source, respectively. Because the diodes are designed to have an approximately flat spectral sensitivity, the output current from each diode is proportional to the x-ray power. The nickel bolometers are fielded at a slightly different angle from the array-diode combinations, and view (without pinhole attenuation) the same x-ray source. The bolometers measure the total x-ray energy radiated by the source and--on every shot--provide an in situ calibration of the array-diode combinations. Two array-diode pairs and two bolometers are fielded to reduce random uncertainties. An analytic model (which accounts for pinhole-diffraction effects) of the sensitivity of an array-diode combination is presented

Ecological radiation protection criteria for nuclear power

International Nuclear Information System (INIS)

Kryshev, I.I.

1993-01-01

By now a large quantity of radioactive hazards of all sizes and shapes has accumulated in Russia. They include RBMK, VVER, and BN (fast-neutron) nuclear power plants, nuclear fuel processing plants, radioactive waste dumps, ships with nuclear power units, etc. In order to evaluate the radioecological situation correctly, the characteristics of the radioactive contamination must be compiled in these areas with some system of criteria which will provide an acceptable level of ecological safety. Currently health criteria for radiation protection are, which are oriented to man's radiation protection, predominate. Here the concept of a thresholdless linear dose-response dependence, which has been confirmed experimentally only at rather high doses (above 1 Gy), is taken as the theoretical basis for evaluating and normalizing radiation effects. According to one opinion, protecting people against radiation is sufficient to protect other types of organisms, although they are not necessarily of the same species. However, from the viewpoint of ecology, this approach is incorrect, because it does not consider radiation dose differences between man and other living organisms. The article discusses dose-response dependences for various organisms, biological effects of ionizing radiation, and appropriate radiation protection criteria

Peak radiated power measurement of the DOE Mark II container tag with integrated ST-676 sensor radio frequency identification device.

Energy Technology Data Exchange (ETDEWEB)

Jursich, Mark

2010-04-01

The total peak radiated power of the Department of Energy Mark II container tag was measured in the electromagnetic reverberation chamber facility at Sandia National Laboratories. The tag's radio frequency content was also evaluated for possible emissions outside the intentional transmit frequency band. No spurious emissions of any significance were found, and the radiated power conformed to the manufacturer's specifications.

Distributing radiation management system of nuclear power plants

International Nuclear Information System (INIS)

Mihoya, Eiichi; Akashi, Michio

1999-01-01

The importance of radiation management for nuclear facilities including nuclear power plants has increased as the general public understanding has progressed, and necessary information for management must be processed exactly and quickly. In nuclear power plants, radiation management is performed by each individual operation, and collected information is managed by the system of each operation. The distributing radiation management system has been developed aiming to use a general-purpose LAN and make quick and efficient use of information managed by individual operations. This paper describes the system configuration and functions. (author)

Ultra-low power high temperature and radiation hard complementary metal-oxide-semiconductor (CMOS) silicon-on-insulator (SOI) voltage reference.

Science.gov (United States)

Boufouss, El Hafed; Francis, Laurent A; Kilchytska, Valeriya; Gérard, Pierre; Simon, Pascal; Flandre, Denis

2013-12-13

This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40-200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si) performed at three different temperatures (room temperature, 100 °C and 200 °C). The maximum drift of the reference voltage V(REF) depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μW at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of V(REF) and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

Standalone, battery powered radiation monitors for accelerator electronics

CERN Document Server

Wijnands, T; Spiezia, G

2009-01-01

A technical description of the design of a new type of radiation monitors is given. The key point in the design is the low power consumption inferior to 17 mW in radiation sensing mode and inferior to 0.3 mW in standby mode. The radiation monitors can operate without any external power or signal cabling and measure and store radiation data for a maximum period of 800 days. To read the radiation data, a standard PC can be connected via a USB interface to the device at any time. Only a few seconds are required to read out a single monitor. This makes it possible to survey a large network of monitoring devices in a short period of time, for example during a stop of the accelerator.

Power components behavior under nuclear radiations

International Nuclear Information System (INIS)

Jaureguy, J.C.; Azais, B.

1989-01-01

Many apparatus, either fixed or on-board of vehicles, use power converters. The most common scheme includes chopper with bipolar transistors. In case of nuclear radiations, these equipments may be severely damaged. Depending on the disturbance level, the need for changes in power transistor technology has to be considered or not [fr

Natural radiation focused by power lines: new evidence

Energy Technology Data Exchange (ETDEWEB)

Hopwood, Anthony

1992-11-01

Scientists searching for a mechanism to explain increases in the incidence of cancer among those living in close proximity to power lines could have been looking in the wrong place. New evidence suggests that instead of trying to find an as yet unproven cellular reaction to the presence of the power-line's magnetic fields, researchers should investigate power lines as concentrators of potentially damaging natural sky radiation. If accepted, a clear link between a known biological cell damage mechanism and power lines will have been established, triggering a reassessment of the independent studies recording statistical increases in cancer incidence around power lines. The evidence stems from recordings showing concentrations of background solar radiation under power lines - a direction of enquiry prompted by a chance observation made during a British Astronomical Association experiment. (Author).

CARS measurement of vibrational and rotational temperature with high power laser and high speed visualization of total radiation behind hypervelocity shock waves of 5-7km/s

Science.gov (United States)

Sakurai, Kotaro; Bindu, Venigalla Hima; Niinomi, Shota; Ota, Masanori; Maeno, Kazuo

2010-09-01

Coherent Anti-Stokes Raman Spectroscopy (CARS) method is commonly used for measuring molecular structure or condition. In the aerospace technology, this method is applies to measure the temperature in thermic fluid with relatively long time duration of millisecond or sub millisecond. On the other hand, vibrational/rotational temperatures behind hypervelocity shock wave are important for heat-shield design in phase of reentry flight. The non-equilibrium flow with radiative heating from strongly shocked air ahead of the vehicles plays an important role on the heat flux to the wall surface structure as well as convective heating. In this paper CARS method is applied to measure the vibrational/rotational temperature of N2 behind hypervelocity shock wave. The strong shock wave in front of the reentering space vehicles can be experimentally realigned by free-piston, double-diaphragm shock tube with low density test gas. However CARS measurement is difficult for our experiment. Our measurement needs very short pulse which order of nanosecond and high power laser for CARS method. It is due to our measurement object is the momentary phenomena which velocity is 7km/s. In addition the observation section is low density test gas, and there is the strong background light behind the shock wave. So we employ the CARS method with high power, order of 1J/pulse, and very short pulse (10ns) laser. By using this laser the CARS signal can be acquired even in the strong radiation area. Also we simultaneously try to use the CCD camera to obtain total radiation with CARS method.

Effects of radiation and apolipoprotein E on lipid profile among workers of nuclear power plants in Korea

International Nuclear Information System (INIS)

Ki-Eun Moon; Mee-Seon Jung; Suk-Hee Sung; Youn-Koun Chang; Il-Keun Park; Yun-Mi Paek; Tae-In Choi; Soo-Geun Kim

2007-01-01

Complete text of publication follows. Several studies reported that the radiation was positively related to fatty liver, low HDL cholesterol, and hypertriglyceridemia. Genetic polymorphism affect prevalence of chronic disease by molecular epidemiology studies. Apolipoprotein E is an important genetic determinant of cardiovascular disease (CVD), namely through its influence on lipid metabolism. Thus, we investigated whether radiation and apo E polymorphism, and environmental factors contribute to the lipid profile in workers of nuclear power plants in Korea. DNA was extracted from the whole blood of 6896 study subjects (6357 males and 359 females), and apo E polymorphism was investigated using PCR. Plasma lipid profiles were measured by standardized enzymatic procedures and radiation dose was measured by the thermoluminescence dosemeter (TLD). Environmental factors such as exercise, smoking were measured from health management database of KHNP. Total of 6802 subjects (aged 20-58) were investigated and radiation exposure dose was 168.51±463.94 mSv in the recent 1-year dose and 248.24±559.21 mSv in the total accumulative dose. In addition, Apo E polymorphism was associated with significant differences in total cholesterol, HDL cholesterol, radiation dose, AI but others no significant. The multiple regression model showed that total cholesterol was positively correlated with age, SBP, BMI, AI, fasting glucose. HDL cholesterol was negatively correlated with AI. LDL cholesterol was positively correlated with age, BMI, fasting glucose. And triglyceride was significantly correlated in the BMI, AI, somking dose, vegetables but others no significant. Metabolic syndrome did not show any relation to the others; only age, SBP, DBP, BMI, fasting glucose, HOMA-IR influenced. However, there was no significant association between radiation dose and lipid profile. In conclusion, Apo E and well-known variables such as SBP, BMI were significantly associated with lipid profile level

Ultra-Low Power Consuming Direct Radiation Sensors Based on Floating Gate Structures

Directory of Open Access Journals (Sweden)

Evgeny Pikhay

2017-07-01

Full Text Available In this paper, we report on ultra-low power consuming single poly floating gate direct radiation sensors. The developed devices are intended for total ionizing dose (TID measurements and fabricated in a standard CMOS process flow. Sensor design and operation is discussed in detail. Original array sensors were suggested and fabricated that allowed high statistical significance of the radiation measurements and radiation imaging functions. Single sensors and array sensors were analyzed in combination with the specially developed test structures. This allowed insight into the physics of sensor operations and exclusion of the phenomena related to material degradation under irradiation in the interpretation of the measurement results. Response of the developed sensors to various sources of ionizing radiation (Gamma, X-ray, UV, energetic ions was investigated. The optimal design of sensor for implementation in dosimetry systems was suggested. The roadmap for future improvement of sensor performance is suggested.

Radiation induced changes in plasma total protein nitrogen and urinary total nitrogen in desert rodent and albino rats subjected to dietary protein deficiency

International Nuclear Information System (INIS)

Roushdy, H.; El-Husseini, M.; Saleh, F.

1986-01-01

The effect of gamma-irradiation on plasma total protein nitrogen and urinary total nitrogen was studied in the desert rodent, psammomy obesus obesus and albino rats subjected to dietary protein deficiency. In albino rats kept on high protein diet, the radiation syndrome resulted in urine retention, while in those kept on non-protein diet, such phenomenon was recorded only with the high radiation level of 1170r. Radiation exposure to 780 and 1170r caused remarkable diuresis in psammomys obesus obesus whereas they induced significant urine retention in albino rats. The levels of plasma total protein nitrogen and urinary total nitrogen were higher in albino rats maintained on high protein diet than in those kept on non-protein diet. Radiation exposure caused an initial drop in plasma total protein nitrogen concentration, concomitant with an initial rise in total urinary nitrogen, radiation exposure of psammomys obesus obesus caused significant increase in the levels of plasma protein nitrogen and urinary total nitrogen. Psammomys obesus obesus seemed to be more affected by radiation exposure than did the albino rats

Radiation-induced off-state leakage current in commercial power MOSFETs

International Nuclear Information System (INIS)

Dodd, Paul Emerson; Shaneyfelt, Marty Ray; Draper, Bruce Leroy; Felix, James Andrew; Schwank, James Ralph; Dalton, Scott Matthew

2005-01-01

The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO 2 ) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail.

Radiated EMI from power converters

Directory of Open Access Journals (Sweden)

Arnautovski-Toševa Vesna

2005-01-01

Full Text Available With the continuous increase of switching frequency together with the ongoing trend to higher complexity and functionality, power converters as a part of electronic systems have raised more and more electromagnetic energy pollution to the local system environment. In the same time, stringent demands are imposed on the designers of new circuits that electromagnetic interference (EMI has to be suppressed at its source before it is allowed to propagate into other circuits and systems. In this paper, the authors present a full-wave numerical method for calculation and simulation of electromagnetic field radiated by power converter circuitry. The main objective is to analyze the layout geometry in order to obtain competitive PCB layout that will enable suitably attenuated level of the radiated electric field to safe level. By this it would be possible to ensure reliable operation of the sensitive electronic components in the proximity.

Total dose and dose rate radiation characterization of EPI-CMOS radiation hardened memory and microprocessor devices

International Nuclear Information System (INIS)

Gingerich, B.L.; Hermsen, J.M.; Lee, J.C.; Schroeder, J.E.

1984-01-01

The process, circuit discription, and total dose radiation characteristics are presented for two second generation hardened 4K EPI-CMOS RAMs and a first generation 80C85 microprocessor. Total dose radiation performance is presented to 10M rad-Si and effects of biasing and operating conditions are discussed. The dose rate sensitivity of the 4K RAMs is also presented along with single event upset (SEU) test data

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

Guideline on radiation protection requirements for ionizing radiation shielding in nuclear power plants

International Nuclear Information System (INIS)

1988-01-01

The guideline which entered into force on 1 May 1988 stipulates the radiation protection requirements for shielding against ionizing radiation to be met in the design, construction, commissioning, operation, and decommissioning of nuclear power plants

Calibration of radiation monitors at nuclear power plants

International Nuclear Information System (INIS)

Boudreau, L.; Miller, A.D.; Naughton, M.D.

1994-03-01

This work was performed to provide guidance to the utilities in the primary and secondary calibration of the radiation monitoring systems (RMS) installed in nuclear power plants. These systems are installed in nuclear power plants to monitor ongoing processes, identify changing radiation fields, predict and limit personnel radiation exposures and measure and control discharge of radioactive materials to the environment. RMS are checked and calibrated on a continuing basis to ensure their precision and accuracy. This report discusses various approaches towards primary and secondary calibrations of the RMS equipment in light of accepted practices at typical power plants and recent interpretations of regulatory guidance. Detailed calibration techniques and overall system responses, trends, and practices are discussed. Industry, utility, and regulatory sources were contacted to create an overall consensus of the most reasonable approaches to optimizing the performance of this equipment

Survivable pulse power space radiator

Science.gov (United States)

Mims, James; Buden, David; Williams, Kenneth

1989-01-01

A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometeorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length.

Radiation losses and global power balance of JT-60 plasmas

International Nuclear Information System (INIS)

Nishitani, T.; Itami, K.; Nagashima, K.; Tsuji, S.; Hosogane, N.; Yoshida, H.; Ando, T.; Kubo, H.; Takeuchi, H.

1990-01-01

The radiation losses and the global power balance for Ohmic and neutral beam heated plasmas have been investigated in different JT-60 configurations. Discharges with a TiC coated molybdenum wall and with a graphite wall, with limiter, outer and lower X-point configurations have been studied by bolometric measurements, thermocouples and an infrared TV camera. In neutral beam heated outer X-point discharges with a TiC coated molybdenum first wall, the radiation loss of the main plasma was very low (10% of the absorbed power). The radiation loss due to oxygen was dominant in this case. On the contrary, in discharges with TiC coated molybdenum limiters the radiation loss was very high (>60% of the absorbed power). In the discharges with a graphite wall the radiated power from the main plasma was 20-25% for both limiter and lower X-point configurations. In lower X-point discharges the main contributor to the radiation loss was oxygen, whereas in limiter discharges the loss due to carbon was equal to the loss due to oxygen. The radiation loss from the lower X-point divertor increased with increasing electron density of the main plasma. (author). 33 refs, 14 figs, 1 tab

Sandwich Core Heat-Pipe Radiator for Power and Propulsion Systems

Science.gov (United States)

Gibson, Marc; Sanzi, James; Locci, Ivan

2013-01-01

Next-generation heat-pipe radiator technologies are being developed at the NASA Glenn Research Center to provide advancements in heat-rejection systems for space power and propulsion systems. All spacecraft power and propulsion systems require their waste heat to be rejected to space in order to function at their desired design conditions. The thermal efficiency of these heat-rejection systems, balanced with structural requirements, directly affect the total mass of the system. Terrestrially, this technology could be used for thermal control of structural systems. One potential use is radiant heating systems for residential and commercial applications. The thin cross section and efficient heat transportability could easily be applied to flooring and wall structures that could evenly heat large surface areas. Using this heat-pipe technology, the evaporator of the radiators could be heated using any household heat source (electric, gas, etc.), which would vaporize the internal working fluid and carry the heat to the condenser sections (walls and/or floors). The temperature could be easily controlled, providing a comfortable and affordable living environment. Investigating the appropriate materials and working fluids is needed to determine this application's potential success and usage.

Thermal Investigation of Interaction between High-power CW-laser Radiation and a Water-jet

Science.gov (United States)

Brecher, Christian; Janssen, Henning; Eckert, Markus; Schmidt, Florian

The technology of a water guided laser beam has been industrially established for micro machining. Pulsed laser radiation is guided via a water jet (diameter: 25-250 μm) using total internal reflection. Due to the cylindrical jet shape the depth of field increases to above 50 mm, enabling parallel kerfs compared to conventional laser systems. However higher material thicknesses and macro geometries cannot be machined economically viable due to low average laser powers. Fraunhofer IPT has successfully combined a high-power continuous-wave (CW) fiber laser (6 kW) and water jet technology. The main challenge of guiding high-power laser radiation in water is the energy transferred to the jet by absorption, decreasing its stability. A model of laser water interaction in the water jet has been developed and validated experimentally. Based on the results an upscaling of system technology to 30 kW is discussed, enabling a high potential in cutting challenging materials at high qualities and high speeds.

Radiator selection for Space Station Solar Dynamic Power Systems

Science.gov (United States)

Fleming, Mike; Hoehn, Frank

A study was conducted to define the best radiator for heat rejection of the Space Station Solar Dynamic Power System. Included in the study were radiators for both the Organic Rankine Cycle and Closed Brayton Cycle heat engines. A number of potential approaches were considered for the Organic Rankine Cycle and a constructable radiator was chosen. Detailed optimizations of this concept were conducted resulting in a baseline for inclusion into the ORC Preliminary Design. A number of approaches were also considered for the CBC radiator. For this application a deployed pumped liquid radiator was selected which was also refined resulting in a baseline for the CBC preliminary design. This paper reports the results and methodology of these studies and describes the preliminary designs of the Space Station Solar Dynamic Power System radiators for both of the candidate heat engine cycles.

Perspective on radiation from the nuclear power industry

International Nuclear Information System (INIS)

Cohen, B.L.

1990-01-01

Methods for estimating the risk of radiation induced cancer mortality to members of the public are outlined for each element of the nuclear power industry - reactor accidents, routine releases from nuclear plants, transport, mining and milling of uranium, and escape of buried radioactive waste (high level and low level). The results are compared with mortality risks from the air pollution and chemical carcinogens released into the ground in generating the same amount of electricity by coal burning - the latter are thousands of times larger. Radiation from nuclear power is also 1,000 times smaller than that from radon in homes. The amount of money spent to avert a death from nuclear power radiation is in the billion dollar range, whereas lives could be saved from radon in homes for 0.00001 times that cost. Medical screening and highway safety programs can save lives for a similarly low cost

High Power Radiation Tolerant CubeSat Power System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — No vendor has yet to provide a radiation tolerant, high efficiency, small Power Management and Distribution module for the SmallSat and CubeSat market yet. Let alone...

Active control of radiated sound power from a baffled, rectangular panel

DEFF Research Database (Denmark)

Mørkholt, Jakob

1996-01-01

with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over......Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... a broad frequency range using few piezoceramic actuators, provided that an accurate estimate of the sound power is available for minimisation....

Present situation of occupational radiation exposure in nuclear power plants

International Nuclear Information System (INIS)

Imabori, Akira

1979-01-01

The present situation of the radiation exposure of workers, including both employes and subcontractors, in the nuclear power plants in Japan, is presented. Twenty seven nuclear power reactors in operation and under construction are tabulated with the name, the owner, the electric output and the commissioning year of each plant. The results of exposure of the workers in these plants are shown, classifying the dose rate into less than 0.5 rem, 0.5 - 1.5 rem, 1.5 - 2.5 rem, 2.5 - 5 rem and more than 5 rem, and the workers into employes and subcontractors. It is noted that the exposure dose of the subcontractors occupies about 88% of all exposure dose, and the exposure is concentrated during regular inspection period. The exposure dose of about 80% of the workers is less than 0.5 rem, and no one was irradiated more than 5 rem in a year. The total exposure dose, which has especially the tendency of increasing with extended maintenance period and decreasing during plant operation period, shows also the trend of increasing with the lapse of operation years. As for the point of view of whole exposure dose, the value is 0.06 -- 0.43 man-rem/10 6 kWh in 1976 FY. It is considered to be necessary to grasp the total exposure dose of each worker wandering from one plant to another, and the central registration center for the workers in radioactive environment was established in 1978. The whole exposure dose data of each worker are stored in the central computer in this center. This system is highly appreciated in radiation exposure management. The total exposure dose is related to the rate of utilization of nuclear plants, and it is expected to decrease with the decrease of plant outage. (Nakai, Y.)

Practical applications of radiative wireless power transfer

NARCIS (Netherlands)

Pflug, H.; Visser, H.J.; Keyrouz, S.

2015-01-01

For practical use of radiative wireless power transfer (WPT), it is necessary to design a system which is able to supply circuits with a dynamic loading characteristic. In this paper we present a practical way to obtain efficiency and dc output power characteristics of a WPT system. An Avago

Taking SiC Power Devices to the Final Frontier: Addressing Challenges of the Space Radiation Environment

Science.gov (United States)

Lauenstein, Jean-Marie; Casey, Megan

2017-01-01

Silicon carbide power device technology has the potential to enable a new generation of aerospace power systems that demand high efficiency, rapid switching, and reduced mass and volume in order to expand space-based capabilities. For this potential to be realized, SiC devices must be capable of withstanding the harsh space radiation environment. Commercial SiC components exhibit high tolerance to total ionizing dose but to date, have not performed well under exposure to heavy ion radiation representative of the on-orbit galactic cosmic rays. Insertion of SiC power device technology into space applications to achieve breakthrough performance gains will require intentional development of components hardened to the effects of these highly-energetic heavy ions. This work presents heavy-ion test data obtained by the authors over the past several years for discrete SiC power MOSFETs, JFETs, and diodes in order to increase the body of knowledge and understanding that will facilitate hardening of this technology to space radiation effects. Specifically, heavy-ion irradiation data taken under different bias, temperature, and ion beam conditions is presented for devices from different manufacturers, and the emerging patterns discussed.

The feasibility of 10 keV X-ray as radiation source in total dose response radiation test

International Nuclear Information System (INIS)

Li Ruoyu; Li Bin; Luo Hongwei; Shi Qian

2005-01-01

The standard radiation source utilized in traditional total dose response radiation test is 60 Co, which is environment-threatening. X-rays, as a new radiation source, has the advantages such as safety, precise control of dose rate, strong intensity, possibility of wafer-level test or even on-line test, which greatly reduce cost for package, test and transportation. This paper discussed the feasibility of X-rays replacing 60 Co as the radiation source, based on the radiation mechanism and the effects of radiation on gate oxide. (authors)

Basic radiation effects in nuclear power electronics technology

International Nuclear Information System (INIS)

Gover, J.E.; Srour, J.R.

1985-05-01

An overview is presented of the effects of radiation in microelectronics technology. The approach taken throughout these notes is to review microscopic phenomena associated with radiation effects and to show how these lead to macroscopic effects in semiconductor devices and integrated circuits. Bipolar integrated circuits technology is reviewed in Appendix A. Appendix B gives present and future applications of radiation-tolerant microelectronics in nuclear power applications as well as the radiation tolerance requirements of these applications

Safety and Radiation Protection at Swedish Nuclear Power Plants 2005

International Nuclear Information System (INIS)

2006-05-01

-to-date and documented safety analyses must be prepared and actively be included in both the preventive safety work and in connection with plant modifications. The licensees have implemented design analysis projects for a long period of time and clarified and stringent regulations for safety analyses have entered into force in 2005. As a result, updated safety reports exist for many of the facilities and schedules exist for the supplementary work that remains to be done. SKI's reinforced supervision of Barsebaeck 2 continued until the closure of the reactor on May 31, 2005. In SKI's opinion, BKAB mainly handled the lengthy facility closure in a satisfactory manner. The handling of nuclear waste at the nuclear facilities has mainly functioned well. The same applies to the operation of the Repository for Low and Intermediate-level Operational Waste (SFR-1) and the Central Interim Storage Facility for Spent Nuclear Fuel (CLAB). The overall evaluation of the Swedish Radiation Protection Authority (SSI) is that radiation protection at Swedish nuclear power plants has functioned well in 2005. The total radiation dose to the personnel at Swedish nuclear power plants was 9.2 manSv, which agrees with the average value of the total radiation doses over the last five years (9 manSv). No-one received a radiation dose in excess of the established dose limits and the radiation levels in the facilities are largely unchanged compared with previous years. The radiation doses to the public from the Swedish nuclear power plants continue to be low. SSI considers that continuous work is also needed in the future at the facilities to further reduce radioactive releases by applying the best available technique (BAT) and other measures. The control measurements that SSI is conducting on environmental samples from around the nuclear power facilities as well as on radioactive releases to water show a good agreement with the licensees' own measurements

Safety and Radiation Protection at Swedish Nuclear Power Plants 2005

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-05-15

other things. Up-to-date and documented safety analyses must be prepared and actively be included in both the preventive safety work and in connection with plant modifications. The licensees have implemented design analysis projects for a long period of time and clarified and stringent regulations for safety analyses have entered into force in 2005. As a result, updated safety reports exist for many of the facilities and schedules exist for the supplementary work that remains to be done. SKI's reinforced supervision of Barsebaeck 2 continued until the closure of the reactor on May 31, 2005. In SKI's opinion, BKAB mainly handled the lengthy facility closure in a satisfactory manner. The handling of nuclear waste at the nuclear facilities has mainly functioned well. The same applies to the operation of the Repository for Low and Intermediate-level Operational Waste (SFR-1) and the Central Interim Storage Facility for Spent Nuclear Fuel (CLAB). The overall evaluation of the Swedish Radiation Protection Authority (SSI) is that radiation protection at Swedish nuclear power plants has functioned well in 2005. The total radiation dose to the personnel at Swedish nuclear power plants was 9.2 manSv, which agrees with the average value of the total radiation doses over the last five years (9 manSv). No-one received a radiation dose in excess of the established dose limits and the radiation levels in the facilities are largely unchanged compared with previous years. The radiation doses to the public from the Swedish nuclear power plants continue to be low. SSI considers that continuous work is also needed in the future at the facilities to further reduce radioactive releases by applying the best available technique (BAT) and other measures. The control measurements that SSI is conducting on environmental samples from around the nuclear power facilities as well as on radioactive releases to water show a good agreement with the licensees' own measurements.

Organization of radiation protection in German nuclear power stations

International Nuclear Information System (INIS)

1989-01-01

Using the operating handbooks of the nuclear power stations in West Germany, an examination was carried out of how far the existing organisational structure for radiation protection fulfils the requirements for protection and whether a standardisation of the organisation would provide improvements for the protection of the personnel and for the practicability of the radiation protection organisation. In particular, the parts 'Personnel operating organisation', 'Radiation protection order' and 'Maintenance order' of the operating handbook were evaluated and an audit was made of the radiation protection organisation. In general, the result of the assessment is that the organisation of radiation protection does not contradict the orders, guidelines and regulations in any of the nuclear power stations examined. Corresponding to the possibilities of regulating details of the radiation protection organisation within the undertaking, the target of 'protection of the personnel against radioactive irradiation' is achieved by the various organisation structures which are largely equal to the given example. (orig./HP) [de

Occupational radiation exposure at commercial nuclear power reactors, 1978

International Nuclear Information System (INIS)

Brooks, B.G.

1979-11-01

An updated compilation is presented of occupational radiation exposures at commercial nuclear power reactors for the years 1969 through 1978. Data received from the 64 light water cooled reactors (LWRs) that had completed at least one year of commercial operation as of December 31, 1978 are included. This represents an increase of seven reactors over the number contained in last year's report. The total number of personnel monitored at LWRs during 1978 increased by approximately 12% to 76,121. The number of workers that received measurable doses, however, increased only 8% to 45,978. The total collective dose for 1978 is estimated to be 31,806 man-rems, a small decrease from last year's value of 32,511, which results in the average dose per worker decreasing slightly to 0.69 rems. The average collective dose per reactor also decreased, by approximately 15%, to a value of 497 man-rems

Radiation safety and protection on the nuclear power plants

International Nuclear Information System (INIS)

Nosovskij, A.V.; Bogorad, V.I.; Vasil'chenko, V.N.; Klyuchnikov, A.A.; Litvinskaya, T.V.; Slepchenko, A.Yu.

2008-01-01

The main issues of the radiation safety and protection provision on the nuclear power plants are considered in this monograph. The description of the basic sources of the radiation danger on NPPs, the principles, the methods and the means of the safety and radiation monitoring provision are shown. The special attention is paid to the issues of the ionizing radiation regulation

Variability in effective radiating area and output power of new ultrasound transducers at 3 MHz.

Science.gov (United States)

Johns, Lennart D; Straub, Stephen J; Howard, Samuel M

2007-01-01

Spatial average intensity (SAI) is often used by clinicians to gauge therapeutic ultrasound dosage, yet SAI measures are not directly regulated by US Food and Drug Administration (FDA) standards. Current FDA guidelines permit a possible 50% to 150% minimum to maximum range of SAI values, potentially contributing to variability in clinical outcomes. To measure clinical values that describe ultrasound transducers and to determine the degree of intramanufacturer and intermanufacturer variability in effective radiating area, power, and SAI when the transducer is functioning at 3 MHz. A descriptive and interferential approach was taken to this quasi-experimental design. Measurement laboratory. Sixty-six 5-cm(2) ultrasound transducers were purchased from 6 different manufacturers. All transducers were calibrated and then assessed using standardized measurement techniques; SAI was normalized to account for variability in effective radiating area, resulting in an nSAI. Effective radiating area, power, and nSAI. All manufacturers with the exception of Omnisound (P = .534) showed a difference between the reported and measured effective radiating area values (P nSAI (P < .05) than all other manufacturers functioning at 3 MHz. Intramanufacturer variability in SAI ranged from 16% to 35%, and intermanufacturer variability ranged from 22% to 61%. Clinicians should consider treatment values of each individual transducer, regardless of the manufacturer. In addition, clinicians should scrutinize the power calibration and recalibration record of the transducer and adjust clinical settings as needed for the desired level of heating. Our data may aid in explaining the reported heating differences among transducers from different manufacturers. Stricter FDA standards regarding effective radiating area and total power are needed, and standards regulating SAI should be established.

Radiation-induced alternative transcripts as detected in total and polysome-bound mRNA.

Science.gov (United States)

Wahba, Amy; Ryan, Michael C; Shankavaram, Uma T; Camphausen, Kevin; Tofilon, Philip J

2018-01-02

Alternative splicing is a critical event in the posttranscriptional regulation of gene expression. To investigate whether this process influences radiation-induced gene expression we defined the effects of ionizing radiation on the generation of alternative transcripts in total cellular mRNA (the transcriptome) and polysome-bound mRNA (the translatome) of the human glioblastoma stem-like cell line NSC11. For these studies, RNA-Seq profiles from control and irradiated cells were compared using the program SpliceSeq to identify transcripts and splice variations induced by radiation. As compared to the transcriptome (total RNA) of untreated cells, the radiation-induced transcriptome contained 92 splice events suggesting that radiation induced alternative splicing. As compared to the translatome (polysome-bound RNA) of untreated cells, the radiation-induced translatome contained 280 splice events of which only 24 were overlapping with the radiation-induced transcriptome. These results suggest that radiation not only modifies alternative splicing of precursor mRNA, but also results in the selective association of existing mRNA isoforms with polysomes. Comparison of radiation-induced alternative transcripts to radiation-induced gene expression in total RNA revealed little overlap (about 3%). In contrast, in the radiation-induced translatome, about 38% of the induced alternative transcripts corresponded to genes whose expression level was affected in the translatome. This study suggests that whereas radiation induces alternate splicing, the alternative transcripts present at the time of irradiation may play a role in the radiation-induced translational control of gene expression and thus cellular radioresponse.

Occupational radiation exposures at Canadian CANDU nuclear power stations

International Nuclear Information System (INIS)

LeSurf, J.E.; Taylor, G.F.

1982-09-01

In Canada, methods to reduce the radiation exposure to workers at nuclear power reactors have been studied and implemented since the early days of the CANDU reactor program. Close collaboration between the designers, the operators, and the manufacturers has reduced the total exposure at each station, the dose requirement to operate and maintain each successive station compared with earlier stations, and the average annual exposure per worker. Specific methods developed to achieve dose reduction include water chemistry; corrosion resistant materials; low cobalt materials; decontamination; hot filtration, improved equipment reliability, maintainability, and accessibility; improved shielding design and location; planning of work for low exposure; improved operating and maintenance procedures; removal of tritium from D 2 O systems and work environments; improved protective clothing; on-power refuelling; worker awareness and training; and many other small improvements. The 1981 occupational dose productivity factors for Pickering A and Bruce A nuclear generating stations were respectively 0.43 and 0.2 rem/MW(e).a

New-generation low-power radiation survey instruments

International Nuclear Information System (INIS)

Waechter, D.A.; Bjarke, G.O.; Wolf, M.A.; Trujillo, F.; Umbarger, C.J.

1983-01-01

A number of new, ultra-low-powered radiation instruments have recently been developed at Los Alamos. Among these are two instruments which use a novel power source to eliminate costly batteries. The newly developed gamma detecting radiac, nicknamed the Firefly, and the alpha particle detecting instrument, called the Simple Cordless Alpha Monitor, both use recent advances in miniaturization and power-saving electronics to yield devices which are small, rugged, and very power-frugal. The two instruments consume so little power that the need for batteries to run them is eliminated. They are, instead, powered by a charged capacitor which will operate the instruments for an hour or more. Both line power and mechanical sources are used to charge the storage capacitors which power the instruments

Radiated Power and Impurity Concentrations in the EXTRAP-T2R Reversed-Field Pinch

Science.gov (United States)

Corre, Y.; Rachlew, E.; Cecconello, M.; Gravestijn, R. M.; Hedqvist, A.; Pégourié, B.; Schunke, B.; Stancalie, V.

2005-01-01

A numerical and experimental study of the impurity concentration and radiation in the EXTRAP-T2R device is reported. The experimental setup consists of an 8-chord bolometer system providing the plasma radiated power and a vacuum-ultraviolet spectrometer providing information on the plasma impurity content. The plasma emissivity profile as measured by the bolometric system is peaked in the plasma centre. A one dimensional Onion Skin Collisional-Radiative model (OSCR) has been developed to compute the density and radiation distributions of the main impurities. The observed centrally peaked emissivity profile can be reproduced by OSCR simulations only if finite particle confinement time and charge-exchange processes between plasma impurities and neutral hydrogen are taken into account. The neutral hydrogen density profile is computed with a recycling code. Simulations show that recycling on metal first wall such as in EXTRAP-T2R (stainless steel vacuum vessel and molybdenum limiters) is compatible with a rather high neutral hydrogen density in the plasma centre. Assuming an impurity concentration of 10% for oxygen and 3% for carbon compared with the electron density, the OSCR calculation including lines and continuum emission reproduces about 60% of the total radiated power with a similarly centrally peaked emissivity profile. The centrally peaked emissivity profile is due to low ionisation stages and strongly radiating species in the plasma core, mainly O4+ (Be-like) and C3+ Li-like.

Radiated Power and Impurity Concentrations in the EXTRAP-T2R Reversed-Field Pinch

International Nuclear Information System (INIS)

Corre, Y.; Rachlew, E.; Gravestijn, R.M.; Hedqvist, A.; Stancalie, V.

2005-01-01

A numerical and experimental study of the impurity concentration and radiation in the EXTRAP-T2R device is reported. The experimental setup consists of an 8-chord bolometer system providing the plasma radiated power and a vacuum ultraviolet spectrometer providing information on the plasma impurity content. The plasma emissivity profile as measured by the bolometric system is peaked in the plasma centre. A one dimensional Onion Skin Collisional-Radiative model (OSCR) has been developed to compute the density and radiation distributions of the main impurities. The observed centrally peaked emissivity profile can be reproduced by OSCR simulations only if finite particle confinement time and charge-exchange processes between plasma impurities and neutral hydrogen are taken into account. The neutral hydrogen density profile is computed with a recycling code. Simulations show that recycling on metal first wall such as in EXTRAP-T2R (stainless steel vacuum vessel and molybdenum limiters) is compatible with a rather high neutral hydrogen density in the plasma centre. Assuming an impurity concentration of 10% for oxygen and 3% for carbon compared with the electron density, the OSCR calculation including lines and continuum emission reproduces about 60% of the total radiated power with a similarly centrally peaked emissivity profile. The centrally peaked emissivity profile is due to low ionisation stages and strongly radiating species in the plasma core, mainly O 4+ (Be-like) and C 3+ (Li-like)

Relationship between images of risk and anxiety toward radiation. Comparison of radiation from chest X-rays and nuclear power plants

International Nuclear Information System (INIS)

Matsui, Yuko

2003-01-01

In order to clarify the components of people's images of radiation risk and the determinants for the degree of anxiety about radiation exposure, an investigation was conducted. Two kinds of radiation, from nuclear power plants and during a chest X-ray, which are relatively familiar to people, were focused on. As a result, only a 'dread' factor was common to both radiation types of. Although the degree of anxiety toward both types of radiation showed a positive correlation with the 'dread' image, the anxiety toward X-ray radiation showed a negative correlation with the 'feeling of conquest'. Anxiety toward radiation from nuclear power plants had a negative correlation with 'control by experts'. These results suggest that the words radiation from nuclear power plants' evoke an image of a situation with high radiation exposure, which is beyond the experts' control abilities. (author)

Provision of operational radiation protection services at nuclear power plants

International Nuclear Information System (INIS)

1990-01-01

The purpose of this publication is to provide practical guidance on establishing and maintaining a radiation protection programme for a nuclear power plant that is consistent with the optimization process recommended in the Basic Safety Standards. This publication is written with a view to providing guidance to every person associated with the radiation protection programme for a nuclear power plant and develops the theme that radiation protection requires the commitment of all plant staff, including higher levels of executive management. 12 refs, 2 figs

Sound power radiated by sources in diffuse fields

DEFF Research Database (Denmark)

Polack, Jean-Dominique

2000-01-01

Sound power radiated by sources at low frequency notoriously depends on source position. We sampled the sound field of a rectangular room at 18 microphone and 4 source positions. Average power spectra were extrapolated from the reverberant field, taking into account the frequency dependent...

Radiation emergency preparedness in nuclear power plants

International Nuclear Information System (INIS)

Geetha, P.V.; Ramamirtham, B.; Khot, P.

2008-01-01

The purpose of planning for radiation emergency response is to ensure adequate preparedness for protection of the plant personnel and members of the public from significant radiation exposures in the unlikely event of an accident. With a number of safety features in the reactor design and sound operating procedures, the probability of a major accident resulting in the releases of large quantities of radioactivity is extremely small. However, as an abundant cautious approach a comprehensive radiation emergency response preparedness is in place in all the nuclear power plants (NPPs). Radiation Emergency in NPPs is broadly categorized into three types; plant emergency, site emergency and off-site emergency. During off site emergency conditions, based on levels of radiation in the environment, Civil Authorities may impose several counter measures such as sheltering, administering prophylaxis (stable iodine for thyroid blocking) and evacuation of people from the affected area. Environmental Survey Laboratory (ESL) carries out environmental survey extensively in the affected sector identified by the meteorological survey laboratory. To handle emergency situations, Emergency Control Centre with all communication facility and Emergency Equipment Centre having radiation measuring instruments and protective equipment are functional at all NPPs. AERB stipulates certain periodicity for conducting the exercises on plant, site and off site emergency. These exercises are conducted and deficiencies corrected for strengthening the emergency preparedness system. In the case of off site emergency exercise, observers are invited from AERB and Crisis Management Group of Department of Atomic Energy (DAE). The emergency exercises conducted by Nuclear Power Plant Sites have been very satisfactory. (author)

Survey of radiation protection, radiation transport, and shielding information needs of the nuclear power industry. Final report

International Nuclear Information System (INIS)

Maskewitz, B.F.; Trubey, D.K.; Roussin, R.W.; McGill, B.L.

1976-04-01

The Radiation Shielding Information Center (RSIC) is engaged in a program to seek out, organize, and disseminate information in the area of radiation transport, shielding, and radiation protection. This information consists of published literature, nuclear data, and computer codes and advanced analytical techniques required by ERDA, its contractors, and the nuclear power industry to improve radiation analysis and computing capability. Information generated in this effort becomes a part of the RSIC collection and/or data base. The purpose of this report on project 219-1 is to document the results of the survey of information and computer code needs of the nuclear power industry in the area of radiation analysis and protection

Survey of radiation protection, radiation transport, and shielding information needs of the nuclear power industry. Final report

Energy Technology Data Exchange (ETDEWEB)

Maskewitz, B.F.; Trubey, D.K.; Roussin, R.W.; McGill, B.L.

1976-04-01

The Radiation Shielding Information Center (RSIC) is engaged in a program to seek out, organize, and disseminate information in the area of radiation transport, shielding, and radiation protection. This information consists of published literature, nuclear data, and computer codes and advanced analytical techniques required by ERDA, its contractors, and the nuclear power industry to improve radiation analysis and computing capability. Information generated in this effort becomes a part of the RSIC collection and/or data base. The purpose of this report on project 219-1 is to document the results of the survey of information and computer code needs of the nuclear power industry in the area of radiation analysis and protection.

On the electromagnetic fields, Poynting vector, and peak power radiated by lightning return strokes

Science.gov (United States)

Krider, E. P.

1992-01-01

The initial radiation fields, Poynting vector, and total electromagnetic power that a vertical return stroke radiates into the upper half space have been computed when the speed of the stroke, nu, is a significant fraction of the speed of light, c, assuming that at large distances and early times the source is an infinitesimal dipole. The initial current is also assumed to satisfy the transmission-line model with a constant nu and to be perpendicular to an infinite, perfectly conducting ground. The effect of a large nu is to increase the radiation fields by a factor of (1-beta-sq cos-sq theta) exp -1, where beta = nu/c and theta is measured from the vertical, and the Poynting vector by a factor of (1-beta-sq cos-sq theta) exp -2.

Radiation safety for the emergency situation of the power plant accident. Radiation safety in society and its education

International Nuclear Information System (INIS)

Kosako, Toshiso

2012-01-01

Great East Japan Earthquake and Tsunamis, and following Fukushima Daiichi Nuclear Power Accident brought about great impact on society in Japan. Accident analysis of inside reactor was studied by reactor physics or reactor engineering knowledge, while dissipation of a large amount of radioactive materials outside reactor facilities, and radiation and radioactivity effects on people by way of atmosphere, water and soil were dealt with radiation safety or radiation protection. Due to extremely low frequency and experience of an emergency, there occurred a great confusion in the response of electric power company concerned, relevant regulating competent authorities, local government and media, and related scholars and researchers, which caused great anxieties amount affected residents and people. This article described radiation safety in the society and its education. Referring to actual examples, how radiation safety or radiation protection knowledge should be dealt with emergency risk management in the society was discussed as well as problem of education related with nuclear power, radiation and prevention of disaster and fostering of personnel for relevant people. (T. Tanaka)

State of radioactive waste management is power reactor facilities and state of radiation exposure of workers who engaged in radiation works in fiscal 1993

International Nuclear Information System (INIS)

1994-01-01

This report is the summary of the reports on radiation control and others submitted by those who installed practical power reactor facilities based on the relevant law in fiscal 1993. The amounts of release of radioactive gaseous and liquid wastes were sufficiently smaller than the target value of the yearly release control for attaining the target value of dose that the public around the facilities receive. As to the state of control of radioactive solid waste, the amount of drum generation tended to decrease year by year, and the cumulative amount to be preserved tended to level off. The dose equivalent that the individuals who engaged in radiation works received was smaller than the limit value in all nuclear power stations. The total dose equivalent for those workers in fiscal 1993 was 86.65 man Sv. Hereafter, the automation and remote operation of works, the water quality control for reducing crud and so on will be promoted to reduce radiation exposure. The reference data on the state of control of gaseous, liquid and solid wastes, and the state of control of radiation exposure of workers are attached. (K.I.)

Simulation-based Investigation of Electric Power Generation by Using Gamma Radiation from Spent Nuclear Fuel

Energy Technology Data Exchange (ETDEWEB)

Lee, Haneol; Yim, Mansung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2014-05-15

This study investigates the feasibility of using gamma radiation energy from spent nuclear fuels to produce electricity as emergency power source. The proposed electric power system includes electricity generation and storage. Electricity generation was based on conversion of gamma energy to light energy using a scintillator and then to electric energy using a solar cell. Generated electricity was to be stored in a battery as a power source. The efficiency of energy conversion and the extent of the resulting electric power source capability were examined by computer model-based simulation. Main factors which affect to total electric power generated include thermal power of nuclear power plant, average burn-up period for fuel rod, battery charging time, and scintillator thickness. The estimated total power generation and its possible application is discussed. Although the output power increases as scintillator becomes thicker, thick scintillator can be problem because of its high price. There are two ways to solve this problem. The first one is to use thin scintillator to whole fuel assembly area. The second one is to use thick scintillator to limited region. But the current per fuel assembly for the first case for 4000MWth, 72 month burnup is about several to tens of microampere scale, which is too small to charge. Because of this the system is supposed to have thick scintillator system with limited region. Based on the results, the generated electricity is expected to be insufficient to operate the safety injection pumps even at the maximum power output. This may be important for security purposes. Based on the current design, the solar cell efficiency is estimated to be around 1.5-4%. As the efficiency is a strong function of scintillation wavelength, improving the efficiency may be possible by broadening the wavelength through the use of multiple scintillators. Future work will also include validation of the results through experiments, and material reliability

Simulation-based Investigation of Electric Power Generation by Using Gamma Radiation from Spent Nuclear Fuel

International Nuclear Information System (INIS)

Lee, Haneol; Yim, Mansung

2014-01-01

This study investigates the feasibility of using gamma radiation energy from spent nuclear fuels to produce electricity as emergency power source. The proposed electric power system includes electricity generation and storage. Electricity generation was based on conversion of gamma energy to light energy using a scintillator and then to electric energy using a solar cell. Generated electricity was to be stored in a battery as a power source. The efficiency of energy conversion and the extent of the resulting electric power source capability were examined by computer model-based simulation. Main factors which affect to total electric power generated include thermal power of nuclear power plant, average burn-up period for fuel rod, battery charging time, and scintillator thickness. The estimated total power generation and its possible application is discussed. Although the output power increases as scintillator becomes thicker, thick scintillator can be problem because of its high price. There are two ways to solve this problem. The first one is to use thin scintillator to whole fuel assembly area. The second one is to use thick scintillator to limited region. But the current per fuel assembly for the first case for 4000MWth, 72 month burnup is about several to tens of microampere scale, which is too small to charge. Because of this the system is supposed to have thick scintillator system with limited region. Based on the results, the generated electricity is expected to be insufficient to operate the safety injection pumps even at the maximum power output. This may be important for security purposes. Based on the current design, the solar cell efficiency is estimated to be around 1.5-4%. As the efficiency is a strong function of scintillation wavelength, improving the efficiency may be possible by broadening the wavelength through the use of multiple scintillators. Future work will also include validation of the results through experiments, and material reliability

Trends in radiation protection: possible effects on fusion power plant design

International Nuclear Information System (INIS)

Eurajoki, Tapani; Frias, Manuel Pascual; Orlandi, Sergio

2003-01-01

Since the design of fusion power plants involves long-term issues, ranging over several decades, it is useful to try to foresee under what kind of regulations the first fusion plants are to be operated. Application of present radiological regulations and practice to a fusion power plant concept is considered. The current design phase of fusion power plants motivates the top-down dose assessment, but it is crucial to aim at bottom-up assessments to ensure radiation doses as low as reasonably achievable. Since several issues, relating both to our knowledge on radiation as well as to the practice of radiation protection, may change in the future, it is necessary to continuously follow the development in the further design of fusion power plants

High-Density Signal Interface Electromagnetic Radiation Prediction for Electromagnetic Compatibility Evaluation.

Energy Technology Data Exchange (ETDEWEB)

Halligan, Matthew

2017-11-01

Radiated power calculation approaches for practical scenarios of incomplete high- density interface characterization information and incomplete incident power information are presented. The suggested approaches build upon a method that characterizes power losses through the definition of power loss constant matrices. Potential radiated power estimates include using total power loss information, partial radiated power loss information, worst case analysis, and statistical bounding analysis. A method is also proposed to calculate radiated power when incident power information is not fully known for non-periodic signals at the interface. Incident data signals are modeled from a two-state Markov chain where bit state probabilities are derived. The total spectrum for windowed signals is postulated as the superposition of spectra from individual pulses in a data sequence. Statistical bounding methods are proposed as a basis for the radiated power calculation due to the statistical calculation complexity to find a radiated power probability density function.

The new law on radiation and nuclear power

International Nuclear Information System (INIS)

Niittylae, A.

1990-01-01

The Law on Nuclear Energy, which entered into force in 1988, controls the use of nuclear power. The new Law on Radiation is under consideration in the Parliament. The internationally approved main principles on radiation protection are the basis of the law. In the article, these principles and the contents of the law are described

Radiation protection organization in Guangdong Nuclear Power Station (GNPS)

International Nuclear Information System (INIS)

Yang Maochun

1993-01-01

The French way of radiation protection management has been adopted by Guangdong Nuclear Power Station (GNPS) but there are some differences. In this paper author describes radiation protection organization in GNPS, special measures having been taken and the present status

Radiation exposure control of nuclear power plant personnel in the Federal Republic of Germany

International Nuclear Information System (INIS)

Mehl, J.

1980-01-01

The analysis of exposure records of all persons engaged in radiation work at nuclear power plants of the Federal Republic of Germany has shown that annual collective doses increase rapidly with time. The annual gross electrical energy generated from nuclear power also increases rapidly with time, corresponding to about 11% of the total gross electrical energy produced in 1977/78. Therefore, it is obvious that there is an increase of both the risk and the benefit from nuclear power production. Whether in the course of time the situation develops more towards the risk or the benefit side is learned from the history of the annual ratio of the collective dose per gross electrical energy generated. This ratio shows a significant decrease since 1972. The decrease is due to the experience gained from operation of the first-generation plants, which led to several administrative measures aimed at an improved control of the collective doses of power plant personnel in the Federal Republic of Germany. The administrative measures include, among others, the introduction of the following requirements: (a) Everyone who applies for a nuclear power plant construction licence has to provide evidence that, in the design of the plant, full use is made of the experience gained from plants in operation with respect to reduction of collective doses of the power plant personnel. (b) Everyone who engages his employees on radiation work within operations for which an operation licence is required, but which is held by others, requires a special 'contractor licence'. (c) Every person engaged in radiation work on the basis of a contractor licence must carry a special exposure record book which is registered by the competent national authority. (author)

Environmental radioactivity and radiation exposure by radioactive emissions of coal-fired power plants

International Nuclear Information System (INIS)

Jacobi, W.

1981-03-01

On the basis of measurements of the radioactive emissions of a 300 MW coal-fired power plant and of a 600 MW lignite-fired power plant the expected activity increase in air and soil in the environment of both plants is estimated and compared with the normal, natural activity level. Due to these emissions it results for the point of maximum immission a committed effective dose equivalent per GW x a of about 0.2 mrem = 0.002 mSv for the coal-fired plant and of about 0.04 mrem = 0.0004 mSv for the lignite-fired plant. This dose is caused to nearly equal parts by inhalation, ingestion and external γ-radiation. The normalized effective dose equivalent in the environment of the modern coal-fired power plant is in the same order of magnitude like that of a modern pressurized water reactor. The total, collective effective dose equivalent commitment by the annual radioactive emissions of coal-fired power plants in the F.R.Germany is estimated to 2000-6000 Man x rem = 20-60 Man x Sv. This corresponds to a mean per caput-dose in the population of the F.R.Germany of about 0.03-0.1 mrem = 0.0003-0.001 mSv; this is about 0.02-0.06% of the mean normal natural radiation exposure of the population. (orig.) [de

Radiation protection in the Czechoslovak nuclear power plants

International Nuclear Information System (INIS)

Singer, J.; Koc, J.; Hynek, J.; Trousil, J.

1987-01-01

The radiation monitoring by means of the central information system and of autonomous, portable and laboratory devices as well as a brief characteristic of the nuclear power plant radiation fields are described. The new personal dosimetric film and thermoluminescent badges and the method (including the block diagram) for personal dose evaluation are also introduced. Internal contamination monitoring is performed by means of a whole-body counter and excreta sample analysis. Monitoring the influence of effluents from nuclear power plants on environment in Czechoslovakia is based on significant radionuclide measurements in ventilation stacks and in the environment, also by means of the telemetric system, all in connection with mathematical models. (author)

Design aspects of radiation protection for nuclear power plants

International Nuclear Information System (INIS)

1985-01-01

This Safety Guide deals with the provisions to be made in the design of thermal neutron reactor power plants to protect site personnel and the public from undue exposure to ionizing radiation during operational states and accident conditions. The effective radiation protection is a combination of good design, high quality construction and proper operation. The document gives guidance on how to satisfy the objectives contained in Subsection 2.2 and Section 9 of the Code of Practice on Design for Safety of Nuclear Power Plants

Two dimensional radiated power diagnostics on Alcator C-Mod

International Nuclear Information System (INIS)

Reinke, M. L.; Hutchinson, I. H.

2008-01-01

The radiated power diagnostics for the Alcator C-Mod tokamak have been upgraded to measure two dimensional structure of the photon emissivity profile in order to investigate poloidal asymmetries in the core radiation. Commonly utilized unbiased absolute extreme ultraviolet (AXUV) diode arrays view the plasma along five different horizontal planes. The layout of the diagnostic set is shown and the results from calibrations and recent experiments are discussed. Data showing a significant, 30%-40%, inboard/outboard emissivity asymmetry during ELM-free H-mode are presented. The ability to use AXUV diode arrays to measure absolute radiated power is explored by comparing diode and resistive bolometer-based emissivity profiles for highly radiative L-mode plasmas seeded with argon. Emissivity profiles match in the core but disagree radially outward resulting in an underprediction of P rad of nearly 50% by the diodes compared to P rad determined using resistive bolometers.

Two dimensional radiated power diagnostics on Alcator C-Moda)

Science.gov (United States)

Reinke, M. L.; Hutchinson, I. H.

2008-10-01

The radiated power diagnostics for the Alcator C-Mod tokamak have been upgraded to measure two dimensional structure of the photon emissivity profile in order to investigate poloidal asymmetries in the core radiation. Commonly utilized unbiased absolute extreme ultraviolet (AXUV) diode arrays view the plasma along five different horizontal planes. The layout of the diagnostic set is shown and the results from calibrations and recent experiments are discussed. Data showing a significant, 30%-40%, inboard/outboard emissivity asymmetry during ELM-free H-mode are presented. The ability to use AXUV diode arrays to measure absolute radiated power is explored by comparing diode and resistive bolometer-based emissivity profiles for highly radiative L-mode plasmas seeded with argon. Emissivity profiles match in the core but disagree radially outward resulting in an underprediction of Prad of nearly 50% by the diodes compared to Prad determined using resistive bolometers.

National conference on radiation safety of nuclear power plants and their environmental impacts

International Nuclear Information System (INIS)

Moravek, J.

1989-01-01

The first national conference on radiation safety of nuclear power plants and their environmental impacts was held in Tale (CS), 12 to 15 October, 1987 with the participation of 201 Czechoslovak specialists representing central authorities, research institutes, institutions of higher education, power plants in operation and under construction, water management and hygiene inspection and some production sectors, specialists from Hungary, Poland and the GDR. The participants heard 110 papers. The conference agenda comprised keynote papers presented in plenary session and five specialist sessions: 1. Radiation control of discharges and their surroundings. 2. Monitoring and evaluation of the radiation situation in nuclear power plants. 3. Equipment for monitoring the nuclear power plant and its environs. 4. Mathematical modelling and assessment of the nuclear power plant radiation environmental impact. 5. Evaluation of sources and of the transport of radioactive materials inside the power plant and the minimization of the nuclear power plant's environmental impact. (Z.M.)

Optical radiative properties of ablating polymers exposed to high-power arc plasmas

Science.gov (United States)

Becerra, Marley; Pettersson, Jonas

2018-03-01

The radiative properties of polymers exposed to high-intensity radiation are of importance for the numerical simulation of arc-induced ablation. The paper investigates the optical properties of polymethylmethacrylate PMMA and polyamide PA6 films exposed to high-power arc plasmas, which can cause ablation of the material. A four-flux radiative approximation is first used to estimate absorption and scattering coefficients of the tested materials in the ultraviolet (UV) and in the visible (VIS) ranges from spectrophotometric measurements. The temperature-induced variation of the collimated transmissivity of the polymers is also measured from room temperature to the glass temperature of PMMA and the melting temperature of PA6. Furthermore, band-averaged absorption and scattering coefficients of non-ablating and ablating polymers are estimated from the UV to the short-wavelength infrared (SWIR), covering the range of interest for the simulation of arc-induced ablation. These estimates are obtained from collimated transmissivities measured with an additional in situ photometric system that uses a high-power, transient arc plasma to both illuminate the samples and to induce ablation. It is shown that the increase in the bulk temperature of PA6 leads to a strong reversible increase in collimated transmissivity, significantly reducing the absorption and scattering coefficients of the material. A weaker but opposite effect of temperature on the optical properties is found in PMMA. As a consequence, it is suggested that the absorption coefficient of polymers used for arc-induced ablation estimates should not be taken directly from direct collimated transmissivity measurements at room temperature. The band-averaged radiation measurements also show that the layer of products released by ablation of PMMA produces scattering radiation losses mainly in the VIS-SWIR ranges, which are only a small fraction of the total incident arc radiation. In a similar manner, the ablation layer

Total Risk Management for Low Dose Radiation Exposures

International Nuclear Information System (INIS)

Simic, Z.; Mikulicic, V.; Sterc, D.

2012-01-01

health. This view is supported with numerous evidences, and explained with beneficial effects from the increased activity of immune system activated with small radiation exposures. Finally, theory in between is that small doses are less than linearly proportionally harmful and that they are presenting a much smaller risks than according to the LNT. This view is derived from the use of different evidences. Difficulties to find one single theory about effects of small radiation doses are related to existence of huge variability and uncertainty in the evidence data. This is very hard experimental and theoretical problem. It will require lots of additional research to reduce these uncertainties and find final theory. This might be too late for the number of people affected in different ways with current single most conservative LNT approach. The problem with the conservative LNT regulatory approach is resulting in enormous additional costs of nuclear energy and medical applications. Which is reasonable and acceptable during the regular operation when source is high and concentrated. But, this becomes unreasonable huge economic burden after accidents and for cleanups with nuclear facilities. Similar problem arises with restriction of medical examinations and treatments based on over conservative risk estimate. Special circumstances are with evacuated people from contaminated areas where they are on the one side saved from small radiation exposures, and on the other side exposed to years of life away from their home and with numerous direct and indirect additional risks (i.e., stress, social problems, etc.). It seems reasonable that some alternative (total) risk management approach might be much more suitable for this situation. Evacuation of people from contaminated area with small doses sources should not be done when that induces larger risks from even what is expected from radiation based on LNT. Similar total risk management could be also applied for with medical

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.)

Inclusion of Radiation Environment Variability in Total Dose Hardness Assurance Methodology

Science.gov (United States)

Xapsos, M. A.; Stauffer, C.; Phan, A.; McClure, S. S.; Ladbury, R. L.; Pellish, J. A.; Campola, M. J.; LaBel, K. A.

2016-01-01

Variability of the space radiation environment is investigated with regard to parts categorization for total dose hardness assurance methods. It is shown that it can have a significant impact. A modified approach is developed that uses current environment models more consistently and replaces the radiation design margin concept with one of failure probability during a mission.

Sound radiation quantities arising from a resilient circular radiator.

Science.gov (United States)

Aarts, Ronald M; Janssen, Augustus J E M

2009-10-01

Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are either Stenzel functions (1-(sigma/a)2)n, with sigma the radial coordinate on the radiator, or linear combinations of Zernike functions Pn(2(sigma/a)2-1), with Pn the Legendre polynomial of degree n. Both sets of functions give rise, via King's integral for the pressure, to integrals for the quantities of interest involving the product of two Bessel functions. These integrals have a power series expansion and allow an expression in terms of Bessel functions of the first kind and Struve functions. Consequently, many of the results in [M. Greenspan, J. Acoust. Soc. Am. 65, 608-621 (1979)] are generalized and treated in a unified manner. A foreseen application is for loudspeakers. The relation between the radiated power in the near-field on one hand and in the far field on the other is highlighted.

Genetic effects in children exposed in prenatal period to ionizing radiation after the Chornobyl nuclear power plant accident.

Science.gov (United States)

Stepanova, Ye I; Vdovenko, V Yu; Misharina, Zh A; Kolos, V I; Mischenko, L P

2016-12-01

To study the genetic effects in children exposed to radiation in utero as a result of the Chornobyl nuclear power plant accident accounting the total radiation doses and equivalent radiation doses to the red bone marrow. Incidence of minor developmental anomalies was studied in children exposed to radiation in utero (study group) and in the control group (1144 subjects surveyed in total). Cytogenetic tests using the method of differential G-banding of chromosomes were conducted in 60 children of both study and control groups (10-12-year-olds) and repeatedly in 39 adolescents (15-17-year-olds). A direct correlation was found between the number of minor developmental anomalies and fetal dose of radiation, and a reverse one with fetal gestational age at the time of radiation exposure. Incidence of chromosomal damage in somatic cells of 10-12-year-old children exposed prenatally was associated with radiation dose to the red bone marrow. The repeated testing has revealed that an increased level of chromosomal aberrations was preserved in a third of adolescents. The persons exposed to ionizing radiation at prenatal period should be attributed to the group of carcinogenic risk due to persisting increased levels of chromosome damage. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

Radiation Testing of PICA at the Solar Power Tower

Science.gov (United States)

White, Susan

2010-01-01

Sandia National Laboratory's Solar Power Tower was used to irradiate specimens of Phenolic Impregnated Carbon Ablator (PICA), in order to evaluate whether this thermal protection system material responded differently to potential shock layer radiative heating than to convective heating. Tests were run at 50, 100 and 150 Watts per square centimeter levels of concentrated solar radiation. Experimental results are presented both from spectral measurements on 1- 10 mm thick specimens of PICA, as well as from in-depth temperature measurements on instrumented thicker test specimens. Both spectral measurements and measured in-depth temperature profiles showed that, although it is a porous, low-density material, PICA does not exhibit problematic transparency to the tested high levels of NIR radiation, for all pragmatic cm-to-inch scale thicknesses. PICA acted as a surface absorber to efficiently absorb the incident visible and near infrared incident radiation in the top 2 millimeter layer in the Solar Power Tower tests up to 150 Watts per square centimeter.

Radiation protection during operation of nuclear power plants

International Nuclear Information System (INIS)

1983-01-01

This Guide describes a Radiation Protection Programme for nuclear power plants. It includes: (1) An outline of the basic principles as well as practical aspects of the programme; (2) A description of the responsibilities of the operating organization to establish an effective programme based upon these principles; (3) A description of the administrative and technical measures to establish and implement the programme. This Guide also deals with the operational aspects to be considered by the operating organization in reviewing design in order to facilitate implementation of the Radiation Protection Programme. This Guide covers the requirements for a Radiation Protection Programme for all operational states of the nuclear power plant. It also includes guidelines for handling planned special exposures and for coping with unplanned exposures and contamination of personnel, areas, and equipment. Additional information concerning emergency situations involving releases of radioactive materials is given in Safety Guides 50-SG-O6, ''Preparedness of the Operating Organization (Licensee) for Emergencies at Nuclear Power Plants'', and 50-SG-G6, ''Preparedness of Public Authorities for Emergencies at Nuclear Power Plants''. This Guide covers the principles of dose limitation to site personnel and to the public, but it does not include detailed instructions on the techniques used for the actual measurement and evaluation of the exposures. This Guide does not include detailed instructions on environmental surveys, but it does mention principal steps in environmental monitoring which may be required for confirmation of the acceptability of radioactive discharges

Analyses of occupational radiation exposure received at Gundremmingen nuclear power station, and its implications on the design of current and future power plants

International Nuclear Information System (INIS)

Eickelpasch, N.; Pfeiffer, K.W.; Peter, H.

1977-01-01

In 1976, the 250 MW Gundremmingen nuclear power station (KRB) completed its first decade of operation. The accumulated activity built-up due to corrosion products in the primary system, the condition of the plant and the methods of radiation work management determine the occupational exposure. The development and the general features of these three parameters are presented in detail. Job related exposure accounting has proven to be an effective means of radiation management. By this means up to 90% of the total radiation exposure could be traced with an accuracy of about 10 mrem. It is shown that up to 40% of the total exposure originate not from primary work but from associating jobs, e.g. work area preparation and testing efforts. Especially in this field a remarkable reduction of the occupational dose rate can be achieved by precise planning. The ten-year radiation protection history of KRB served as a design basis with the objective to reduce occupational radiation exposure. Examples are given how this influenced not only the design of relevant systems but also their accomodation, arrangement and shielding with regard to maintenance and repair work during reactor outage. Physical separation of the components and valves from the associated actuators, controls and instruments was provided to reduce personnel radiation exposure during plant operation. Provisions were also made to avoid contamination of the building atmosphere and to reduce the release of radioactivity via the ventilation systems

Radiation burden of population in nuclear power plant siting

International Nuclear Information System (INIS)

Navratil, J.

The significance is discussed of the determination of the radiobiological consequences of normal operation and design basis accidents in nuclear power plant siting. The basic diagram and brief description is given of the programme for calculating the radiation load of the population in the surroundings of the nuclear power plant. The programme consists of two subprogrammes, i.e., the dispersion of radioactive gases (for normal operation and for accidents), the main programme for the determination of biological consequences and one auxiliary programme (the distribution of the population in the surroundings of the power plant). The four most important types of exposure to ionizing radiation are considered, namely inhalation, external irradiation from a cloud, ingestion (water, milk, vegetables), external irradiation from the deposit. (B.S.)

Fundamental rights reflected by the legislation regarding radiation and nuclear power

International Nuclear Information System (INIS)

Han, Eun Ok; Lee, Jae Seong; Cho, Hong Jea

2016-01-01

Despite the visible growth in radiation usage and nuclear power development, the analysis of their relationship with fundamental rights, a subject of public concern regarding issues including the right to health, environmental rights, safety rights, the right to know, the right to development, and the right to life, is currently non-existent. 15-29By examining various fundamental rights in the context of positive laws regarding radiation and nuclear power in an idealistic perspective that guarantees the maximum degree of rights, this paper aims to propose legislative supplements that will lead to improvements in quality of life. In the South Korean Constitution, radiation and nuclear power is a subject incorporating several rights, including at least 12 clauses that are directly related to fundamental rights; these constitutional rights are manifested in the various clauses of the 14 positive laws regarding radiation and nuclear power. The question on the relative importance of each fundamental right as reflected in these positive laws- whether the right to life should be prioritized or considered equal in weight to the right to health, environmental rights, the right to know, and safety rights- requires careful deliberation and is difficult to humanly resolve in the short term. Making policy that expands the usage of radiation and nuclear power while simultaneously preventing their associated risks is an important task for the Republic of Korea, and a proper value judgment is necessary to find a balance in its associated rights

Fundamental rights reflected by the legislation regarding radiation and nuclear power

Energy Technology Data Exchange (ETDEWEB)

Han, Eun Ok [Korea Academy of Nuclear Safety, Seoul (Korea, Republic of); Lee, Jae Seong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Cho, Hong Jea [Korea National Defense University, Goyang (Korea, Republic of)

2016-05-15

Despite the visible growth in radiation usage and nuclear power development, the analysis of their relationship with fundamental rights, a subject of public concern regarding issues including the right to health, environmental rights, safety rights, the right to know, the right to development, and the right to life, is currently non-existent. 15-29By examining various fundamental rights in the context of positive laws regarding radiation and nuclear power in an idealistic perspective that guarantees the maximum degree of rights, this paper aims to propose legislative supplements that will lead to improvements in quality of life. In the South Korean Constitution, radiation and nuclear power is a subject incorporating several rights, including at least 12 clauses that are directly related to fundamental rights; these constitutional rights are manifested in the various clauses of the 14 positive laws regarding radiation and nuclear power. The question on the relative importance of each fundamental right as reflected in these positive laws- whether the right to life should be prioritized or considered equal in weight to the right to health, environmental rights, the right to know, and safety rights- requires careful deliberation and is difficult to humanly resolve in the short term. Making policy that expands the usage of radiation and nuclear power while simultaneously preventing their associated risks is an important task for the Republic of Korea, and a proper value judgment is necessary to find a balance in its associated rights.

New generation low power radiation survey instruments

International Nuclear Information System (INIS)

Waechter, D.A.; Bjarke, G.O.; Trujillo, F.; Umbarger, C.J.; Wolf, M.A.

1984-01-01

A number of new, ultra-low-powered radiation instruments have recently been developed at Los Alamos. Among these are two instruments which use a novel power source to eliminate costly batteries. The newly developed gamma detecting radiac, nicknamed the Firefly, and the alpha particle detecting instrument, called the Simple Cordless Alpha Monitor, both use recent advances in miniaturization and powersaving electronics to yield devices which are small, rugged, and very power-frugal. The two instruments consume so little power that the need for batteries to run them is eliminated. They are, instead, powered by a charged capacitor which will operate the instruments for an hour or more. Use of a capacitor as a power source eliminates many problems commonly associated with battery-operated instruments, such as having to open the case to change batteries, battery storage life, availability of batteries in the field, and some savings in weight. Both line power and mechanical sources are used to charge the storage capacitors which power the instruments

Theoretic simulation for CMOS device on total dose radiation response

International Nuclear Information System (INIS)

He Baoping; Zhou Heqin; Guo Hongxia; He Chaohui; Zhou Hui; Luo Yinhong; Zhang Fengqi

2006-01-01

Total dose effect is simulated for C4007B, CC4007RH and CC4011 devices at different absorbed dose rate by using linear system theory. When irradiation response and dose are linear, total dose radiation and post-irradiation annealing at room temperature are determined for one random by choosing absorbed dose rate, and total dose effect at other absorbed dose rate can be predicted by using linear system theory. The simulating results agree with the experimental results at different absorbed dose rate. (authors)

The computerized radiation control system for the nuclear power plant

International Nuclear Information System (INIS)

Hunamoto, H.; Sato, T.; Taniguchi, K.

1993-01-01

Major works of Radiation control in nuclear power plant consist of occupational exposure control, radiation monitoring of working areas and surveillance of monitoring equipment, environmental monitoring and so on. Since a large amount of data will be generated from these works, therefore use of high performance computers will be indispensable. The systematization is presently being advanced in The Japan Atomic Power Company from this viewpoint and the project is being realized smoothly. The actual state is introduced

Robustness of radiative mantle plasma power exhaust solutions for ITER

International Nuclear Information System (INIS)

Mandrekas, J.; Stacey, W.M.; Kelly, F.A.

1997-01-01

The robustness of impurity-seeded radiative mantle solutions for ITER to uncertainties in several physics and operating parameters is examined. The results indicate that ∼ 50--90% of the input power can be radiated from inside the separatrix with Ne, Ar and Kr injection, without significant detriment to the core power balance or collapse of the edge temperature profile, for a wide range of conditions on the impurity pinch velocity, edge temperature pedestal, and plasma density

New sources of high-power coherent radiation

International Nuclear Information System (INIS)

Sprehngl, F.

1985-01-01

New sources of high-power coherent radiation in the wavelength range from millimeter to ultraviolet are reviewed. Physical mechanisms underlying concepts of free electrons laser, cyclotron resonance laser and other new radiation sources are described. Free electron lasers and cyclotron resonance lasers are shown to suggest excellent possibilities for solving problems of spectroscopy, plasma heating radar and accelerator technology. Results of experiments with free electron laser in the Compton mode using linear accelerators microtrons and storage rings are given. Trends in further investigations are shown

Precise estimation of total solar radiation on tilted surface

African Journals Online (AJOL)

rajeev

rarely available required for precise sizing of energy systems. The total solar radiation at different orientation and slope is needed to calculate the efficiency of the installed solar energy systems. To calculate clearness index (Kt) used by Gueymard (2000) for estimating solar irradiation H, irradiation at the earth's surface has ...

Characterization of Radiation Hardened Bipolar Linear Devices for High Total Dose Missions

Science.gov (United States)

McClure, Steven S.; Harris, Richard D.; Rax, Bernard G.; Thorbourn, Dennis O.

2012-01-01

Radiation hardened linear devices are characterized for performance in combined total dose and displacement damage environments for a mission scenario with a high radiation level. Performance at low and high dose rate for both biased and unbiased conditions is compared and the impact to hardness assurance methodology is discussed.

Scheduled Operation of PV Power Station Considering Solar Radiation Forecast Error

Science.gov (United States)

Takayama, Satoshi; Hara, Ryoichi; Kita, Hiroyuki; Ito, Takamitsu; Ueda, Yoshinobu; Saito, Yutaka; Takitani, Katsuyuki; Yamaguchi, Koji

Massive penetration of photovoltaic generation (PV) power stations may cause some serious impacts on a power system operation due to their volatile and unpredictable output. Growth of uncertainty may require larger operating reserve capacity and regulating capacity. Therefore, in order to utilize a PV power station as an alternative for an existing power plant, improvement in controllability and adjustability of station output become very important factor. Purpose of this paper is to develop the scheduled operation technique using a battery system (NAS battery) and the meteorological forecast. The performance of scheduled operation strongly depends on the accuracy of solar radiation forecast. However, the solar radiation forecast contains error. This paper proposes scheduling method and rescheduling method considering the trend of forecast error. More specifically, the forecast error scenario is modeled by means of the clustering analysis of the past actual forecast error. Validity and effectiveness of the proposed method is ascertained through computational simulations using the actual PV generation data monitored at the Wakkanai PV power station and solar radiation forecast data provided by the Japan Weather Association.

Measurement of gamma radiation doses in nuclear power plant environment

International Nuclear Information System (INIS)

Bochvar, I.A.; Keirim-Markus, I.B.; Sergeeva, N.A.

1976-01-01

Considered are the problems of measuring gamma radiation dose values and the dose distribution in the nuclear power plant area with the aim of estimating the extent of their effect on the population. Presented are the dosimeters applied, their distribution throughout the controlled area, time of measurement. The distribution of gamma radiation doses over the controlled area and the dose alteration with the increase of the distance from the release source are shown. The results of measurements are investigated. The conclusion is made that operating nuclear power plants do not cause any increase in the gamma radiation dose over the area. Recommendations for clarifying the techniques for using dose-meters and decreasing measurement errors are given [ru

Single-dose radiation therapy for prevention of heterotopic ossification after total hip arthroplasty

International Nuclear Information System (INIS)

Healy, W.L.; Lo, T.C.; Covall, D.J.; Pfeifer, B.A.; Wasilewski, S.A.

1990-01-01

Single-dose radiation therapy was prospectively evaluated for its efficacy in prevention of heterotopic ossification in patients at high risk after total hip arthroplasty. Thirty-one patients (34 hips) were treated between 1981 and 1988. Risk factors for inclusion in the protocol included prior evidence of heterotopic ossification, ankylosing spondylitis, and diffuse idiopathic skeletal hyperostosis. Patients with hypertrophic osteoarthritis or traumatic arthritis with osteophytes were not included. Operations on 34 hips included 19 primary total and 11 revision total hip arthroplasties and 4 excisions of heterotopic ossification. All patients received radiotherapy to the hip after operation with a single dose of 700 centigray. Radiotherapy is recommended on the first postoperative day. After this single-dose radiation treatment, no patient had clinically significant heterotopic ossification. Recurrent disease developed in two hips (6%), as seen on radiography (grades 2 and 3). This series documents a 100% clinical success rate and a 94% radiographic success rate in preventing heterotopic ossification in patients at high risk after total hip arthroplasty. Single-dose radiotherapy is as effective as other radiation protocols in preventing heterotopic ossification after total hip arthroplasty. It is less expensive and easier to administer than multidose radiotherapy

Compression and radiation of high-power short rf pulses. II. A novel antenna array design with combined compressor/radiator elements

KAUST Repository

Sirenko, Kostyantyn

2011-01-01

The paper discusses the radiation of compressed high power short RF pulses using two different types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a compressor and a radiator. The studies on the monopole antenna demonstrate the possibility of a high power short RF pulse\\'s efficient radiation even using simple antennas. The studies on the novel array design demonstrate that a reduced size array with lower pulse distortion and power decay can be constructed by assembling the array from elements each of which integrates a compressor and a radiator. This design idea can be used with any type of antenna array; in this work it is applied to a phased array.

Use of radiation and radiation practices 1994. Events and statistics

International Nuclear Information System (INIS)

Havukainen, R.

1995-05-01

In Finland, there were 1,745 valid safety licences for the use of radiation at the end of 1994. In addition, 2,050 sites were included in the compulsory registration for dental x-ray diagnostics. The register of the Finnish Centre for Radiation and Nuclear Safety listed 12,794 radiation sources and 316 radionuclide laboratories. The import of radioactive substances amounted to 4.6x10 15 Bq and export to 2.2x10 13 Bq. A total of 1.4x10 13 Bq of short-lived radionuclides were produced in Finland. Workers monitored for radiation exposure included 11,147 employees on 1,294 work sites. Of these, 27% received an annual dose exceeding the recording threshold. The total dose recorded in the dose register (sum of personal dosemeter readings) was 75 man Sv in 1994, nuclear power plant employees accounting for 70% of this total. The annual dosemeter reading of ten medical doctors (radiologists, international radiologists and cardiologists) and five nuclear power plant employees was equal to or in excess of 20 mSv. Effective dose, however, did not exceed the dose limit of 50 mSv established for a one-year monitoring period

Physics contributions to radiation protection in nuclear power plants

International Nuclear Information System (INIS)

Krueger, F.W.

1980-01-01

Physical research and physical methods can essentially contribute to radiation protection in nuclear power plants. With their aid, properties of radiation sources can be determined, and calculations of radiation shields can be performed. In the present paper, such tasks are analyzed, the state of the art of their solution is evaluated, and trends of further work are shown. Focal points of the present study are the calculation of properties of radiation sources outside the reactor (fission products, activated corrosion products, decontamination facilities for contaminated media), exact and engineering methods for calculating radiation fields also in inhomogeneous shields, and classification of concretes for gamma-ray shielding. Objectives, possibilities, and problems of standardization of such activities are discussed. (author)

Development of a research reactor power measurement system using Cherenkov radiation

Energy Technology Data Exchange (ETDEWEB)

Salles, Brício M.; Mesquita, Amir Z., E-mail: briciomares@hotmail.com, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-11-01

Nuclear research reactors are usually located in open pools, to allow visibility to the core and bluish luminosity of Cherenkov radiation. Usually the thermal power released in these reactors is monitored by chambers that measure the neutron flux, as it is proportional to the power. There are other methods used for power measurement, such as monitoring the core temperature and the energy balance in the heat exchanger. The brightness of Cherenkov's radiation is caused by the emission of visible electromagnetic radiation (in the blue band) by charged particles that pass through an insulating medium (water in nuclear research reactors) at a speed higher than that of light in this medium. This effect was characterized by Pavel Cherenkov, which earned him the Nobel Prize for Physics in 1958. The project's objective is to develop an innovative and alternative method for monitoring the power of nuclear research reactors. It will be performed by analyzing and monitoring the intensity of luminosity generated by Cherenkov radiation in the reactor core. This method will be valid for powers up to 250 kW, since above that value the luminosity saturates, as determined by previous studies. The reactor that will be used to test the method is the TRIGA, located at Nuclear Technology Development Center (CDTN), which currently has a maximum operating power of 250 kW. This project complies with International Atomic Energy Agency (IAEA) recommendations on reactor safety. It will give more redundancy and diversification in this measure and will not interfere with its operation. (author)

Development of a research reactor power measurement system using Cherenkov radiation

International Nuclear Information System (INIS)

Salles, Brício M.; Mesquita, Amir Z.

2017-01-01

Nuclear research reactors are usually located in open pools, to allow visibility to the core and bluish luminosity of Cherenkov radiation. Usually the thermal power released in these reactors is monitored by chambers that measure the neutron flux, as it is proportional to the power. There are other methods used for power measurement, such as monitoring the core temperature and the energy balance in the heat exchanger. The brightness of Cherenkov's radiation is caused by the emission of visible electromagnetic radiation (in the blue band) by charged particles that pass through an insulating medium (water in nuclear research reactors) at a speed higher than that of light in this medium. This effect was characterized by Pavel Cherenkov, which earned him the Nobel Prize for Physics in 1958. The project's objective is to develop an innovative and alternative method for monitoring the power of nuclear research reactors. It will be performed by analyzing and monitoring the intensity of luminosity generated by Cherenkov radiation in the reactor core. This method will be valid for powers up to 250 kW, since above that value the luminosity saturates, as determined by previous studies. The reactor that will be used to test the method is the TRIGA, located at Nuclear Technology Development Center (CDTN), which currently has a maximum operating power of 250 kW. This project complies with International Atomic Energy Agency (IAEA) recommendations on reactor safety. It will give more redundancy and diversification in this measure and will not interfere with its operation. (author)

Occupational radiation exposure at commercial nuclear power reactors, 1981. Annual report

International Nuclear Information System (INIS)

Brooks, B.G.

1982-11-01

This report presents an updated compilation of occupational radiation exposures at commercial nuclear power reactors for the years 1969 through 1981. This year's report contains data received from the 70 light water cooled reactors (LWRs) and one high temperature gas cooled reactor that had been declared to be in commercial operation for at least one full year as of December 31, 1981. This represents an increase of two reactors over the number contained in last year's report. The total number of personnel monitored at LWRs in 1981 was 124,504, a slight decrease from that found in 1980. The number of workers that received measurable doses during 1981 was 82,183 which is about 2000 more than that found in 1980. The total collective dose at LWRs for 1981 is estimated to be 54,142 man-rems, which is only about 350 man-rems more than that reported in 1980. The report also presents a summary and some analyses of the exposure data contained in the termination reports that have been submitted by nuclear power licensees to the Commission pursuant to 10 CFR Section 20.408. As of December 31, 1981, personal identification and exposure information had been collected and computerized for some 210,000 of these terminating reactor personnel

A self-powered thin-film radiation detector using intrinsic high-energy current

Energy Technology Data Exchange (ETDEWEB)

Zygmanski, Piotr, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Sajo, Erno, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Physics and Applied Physics, Medical Physics Program, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States)

2016-01-15

Purpose: The authors introduce a radiation detection method that relies on high-energy current (HEC) formed by secondary charged particles in the detector material, which induces conduction current in an external readout circuit. Direct energy conversion of the incident radiation powers the signal formation without the need for external bias voltage or amplification. The detector the authors consider is a thin-film multilayer device, composed of alternating disparate electrically conductive and insulating layers. The optimal design of HEC detectors consists of microscopic or nanoscopic structures. Methods: Theoretical and computational developments are presented to illustrate the salient properties of the HEC detector and to demonstrate its feasibility. In this work, the authors examine single-sandwiched and periodic layers of Cu and Al, and Au and Al, ranging in thickness from 100 nm to 300 μm and separated by similarly sized dielectric gaps, exposed to 120 kVp x-ray beam (half-value thickness of 4.1 mm of Al). The energy deposition characteristics and the high-energy current were determined using radiation transport computations. Results: The authors found that in a dual-layer configuration, the signal is in the measurable range. For a defined total detector thickness in a multilayer structure, the signal sharply increases with decreasing thickness of the high-Z conductive layers. This paper focuses on the computational results while a companion paper reports the experimental findings. Conclusions: Significant advantages of the device are that it does not require external power supply and amplification to create a measurable signal; it can be made in any size and geometry, including very thin (sub-millimeter to submicron) flexible curvilinear forms, and it is inexpensive. Potential applications include medical dosimetry (both in vivo and external), radiation protection, and other settings where one or more of the above qualities are desired.

High-power beam-based coherently enhanced THz radiation source

Directory of Open Access Journals (Sweden)

Yuelin Li (李跃林

2008-08-01

Full Text Available We propose a compact Smith-Purcell radiation device that can potentially generate high average power THz radiation with high conversion efficiency. The source is based on a train of short electron bunches from an rf photoemission gun at an energy of a few MeV. Particle tracking simulation and analysis show that, with a beam current of 1 mA, it is feasible to generate hundreds of watts of narrow-band THz radiation at a repetition rate of 1 MHz.

Computer simulation of ionizing radiation burnout in power MOSFETs

International Nuclear Information System (INIS)

Keshavarz, A.A.; Fischer, T.A.; Dawes, W.R. Jr.; Hawkins, C.F.

1988-01-01

The transient response of a power MOSFET device to ionizing radiation was examined using the BAMBI device simulator. The radiation rate threshold for burnout was determined for several different cases. The burnout mechanism was attributed to current-induced avalanche. The effects of the applied drain-source voltage and the base width of the parasitic bipolar device on the threshold level were modeled. It was found that the radiation rate threshold is lower at higher drain-source voltages or narrower bases. 8 refs., 17 figs

ELBE Center for High-Power Radiation Sources

Directory of Open Access Journals (Sweden)

Peter Dr. Michel

2016-01-01

Full Text Available In the ELBE Center for High-Power Radiation Sources, the superconducting linear electron accelerator ELBE, serving  two free electron lasers, sources for intense coherent THz radiation, mono-energetic positrons, electrons, γ-rays, a neutron time-of-flight system as well as two synchronized ultra-short pulsed Petawatt laser systems are collocated. The characteristics of these beams make the ELBE center a unique research instrument for a variety of external users in fields ranging from material science over nuclear physics to cancer research, as well as scientists of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR.

Study of the fluctuations of the partial and total radiative widths by neutron capture resonance method; Etude des fluctuations des largeurs radiatives partielles et totales par la capture des neutrons de resonance

Energy Technology Data Exchange (ETDEWEB)

Huynh, V D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-06-01

Radiative capture experiments by neutron time-of-flight methods have been made for following studies: distribution of partial radiative widths, effects of correlation between different radiative transitions, fluctuations of total radiative widths {gamma}{sub {gamma}} from resonance to resonance, variation of {gamma}{sub {gamma}} with number of mass and the search for the existence of potential capture. Also, some other experiments with the use of neutron capture gamma-rays spectra have been investigated. (author) [French] Par la capture des neutrons de resonance dont les energies sont selectionnees a l'aide de la technique du temps de vol, differents types d'experiences ont ete realisees concernant les etudes des distributions des largeurs radiatives partielles, des effets de correlation entre differentes voies de desexcitation, de la fluctuation des largeurs radiatives totales {gamma}{sub {gamma}} de resonance a resonance, de la variation de la quantite {gamma}{sub {gamma}} en fonction du nombre de masse et de la mise en evidence de l'existence du processus de capture potentielle. Quelques autres applications de l'emploi du spectre de rayons gamma ont egalement ete presentees. (auteur)

Optimal Power Allocation for Downstream xDSL With Per-Modem Total Power Constraints: Broadcast Channel Optimal Spectrum Balancing (BC-OSB)

Science.gov (United States)

Le Nir, Vincent; Moonen, Marc; Verlinden, Jan; Guenach, Mamoun

2009-02-01

Recently, the duality between Multiple Input Multiple Output (MIMO) Multiple Access Channels (MAC) and MIMO Broadcast Channels (BC) has been established under a total power constraint. The same set of rates for MAC can be achieved in BC exploiting the MAC-BC duality formulas while preserving the total power constraint. In this paper, we describe the BC optimal power allo- cation applying this duality in a downstream x-Digital Subscriber Lines (xDSL) context under a total power constraint for all modems over all tones. Then, a new algorithm called BC-Optimal Spectrum Balancing (BC-OSB) is devised for a more realistic power allocation under per-modem total power constraints. The capacity region of the primal BC problem under per-modem total power constraints is found by the dual optimization problem for the BC under per-modem total power constraints which can be rewritten as a dual optimization problem in the MAC by means of a precoder matrix based on the Lagrange multipliers. We show that the duality gap between the two problems is zero. The multi-user power allocation problem has been solved for interference channels and MAC using the OSB algorithm. In this paper we solve the problem of multi-user power allocation for the BC case using the OSB algorithm as well and we derive a computational efficient algorithm that will be referred to as BC-OSB. Simulation results are provided for two VDSL2 scenarios: the first one with Differential-Mode (DM) transmission only and the second one with both DM and Phantom- Mode (PM) transmissions.

General aspects of nuclear power, radiation and environmental effects. Chapter 3

International Nuclear Information System (INIS)

1978-01-01

A general introduction to the principles of the functioning of a nuclear reactor and of power plants based on the reactor types at present in use, and likely to be used in the near future (PWR,BWR,FBR,HTGR and CANDU) is given. The general principles of a thermonuclear power plant are also briefly presented, and general safety aspects discussed. The physics of ionising radiations is briefly presented and natural and artificial sources of radiation are discussed. The fuel cycle, from mining to reprocessing and waste disposal and transport, is presented. The behaviour and effects of radioactive substances in the biosphere, radiation doses, and biological effects of ionising radiation are discussed. In conclusion there is an appendix in which the main characteristics of a number of elements which have important radioactive isotopes are presented. (JIW)

The total dose effects on the 1/f noise of deep submicron CMOS transistors

International Nuclear Information System (INIS)

Hu Rongbin; Wang Yuxin; Lu Wu

2014-01-01

Using 0.18 μm CMOS transistors, the total dose effects on the 1/f noise of deep-submicron CMOS transistors are studied for the first time in mainland China. From the experimental results and the theoretic analysis, we realize that total dose radiation causes a lot of trapped positive charges in STI (shallow trench isolation) SiO 2 layers, which induces a current leakage passage, increasing the 1/f noise power of CMOS transistors. In addition, we design some radiation-hardness structures on the CMOS transistors and the experimental results show that, until the total dose achieves 750 krad, the 1/f noise power of the radiation-hardness CMOS transistors remains unchanged, which proves our conclusion. (semiconductor devices)

Radiation characteristics of input power from surface wave sustained plasma antenna

Energy Technology Data Exchange (ETDEWEB)

Naito, T., E-mail: Naito.Teruki@bc.MitsubishiElectric.co.jp [Advanced Technology R& D Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Yamaura, S. [Information Technology R& D Center, Mitsubishi Electric Corporation, Kamakura, Kanagawa 247-8501 (Japan); Fukuma, Y. [Communication System Center, Mitsubishi Electric Corporation, Amagasaki, Hyogo 661-8661 (Japan); Sakai, O. [Department of Electronic System Engineering, The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

2016-09-15

This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

Radiation characteristics of input power from surface wave sustained plasma antenna

International Nuclear Information System (INIS)

Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.

2016-01-01

This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.

Real-time assessment of radiation burden of the population in the vicinity of nuclear power plants during radiation accidents

International Nuclear Information System (INIS)

Stubna, M.

1986-01-01

The method is presented of real-time calculation of the radiation situation (dose equivalents) in the environs of a nuclear power plant in case of an accident involving the release of radioactive substances into the atmosphere, this for the potentially most significant exposure paths in the initial and medium stages of the accident. The method allows to take into consideration the time dependence of the rate of radioactive substance release from the nuclear power plant and to assess the development in space and time of the radiation situation in the environs of the nuclear power plant. The use of the method is illustrated by an example of the calculation of the development of the radiation situation for model accidents of a hypothetical PWR with containment. (author)

Focusing of cosmic radiation near power lines. A theoretical approach

International Nuclear Information System (INIS)

Skedsmo, A.; Vistnes, A.I.

1997-02-01

The purpose of this work was to determine if, and to what extent, cosmic radiation can be focused by power lines. As an alternative to experimental measurements, a computer program was developed for simulation of particle trajectories. Starting from given initial values, the cosmic particles trajectories through the electromagnetic field surrounding power lines were simulated. Particular efforts have been made to choose initial values which represent the actual physical condition of the cosmic radiation at ground level. The results show an average decrease in the particle flux density in an area below a power line and a corresponding increased flux between 12 m and 45 m on either side of the centre of the power line. The average shift in flux density is, however, extremely small (less than 0.1%) and probably not measurable with existing detector technology. 11 refs., 4 figs., 2 tabs

Total and Differential Efficiencies for a Circular Detector Viewing a Circular Radiator of Finite Thickness

Energy Technology Data Exchange (ETDEWEB)

Lauber, A; Tollander, B

1967-08-15

Total and differential detection efficiencies have been computed for a circular detector viewing a circular radiator of finite thickness. Isotropic, cosines and n-p scattering angular emission distributions of the radiated particles are considered. Tables are given for the total efficiencies as well as for the differential efficiencies in the n-p scattering case.

Methodical recommendations for power unit comprehensive engineering and radiation survey

International Nuclear Information System (INIS)

Nosovskij, A.V.

2000-01-01

The article describes power unit radiation survey methods developed and applied during conduction of Ch NPP unit I Comprehensive Engineering Radiation Survey. Special requirements for units under decommissioning, main survey principals, criteria for definition of volume and the order of survey for various systems of a NPP Unit are included

Generation of high-power terahertz radiation by femtosecond-terawatt lasers

International Nuclear Information System (INIS)

Nashima, Shigeki; Hosoda, Makoto; Daido, Hiroyuki

2007-01-01

We observed electromagnetic waves in the terahertz (THz) frequency range from a Ti foil excited by tabletop terawatt (T-cube) laser pulses. The radiation power was increased drastically with increasing its laser power. We also investigated the polarization characteristics of the sub-terahertz wave. It is found that the polarization of the radiated sub-terahertz waves was parallel to the incident beam plane, which is independent on the pump laser polarization. These results indicate transient electric field to the incident plane is generated by laser-plasma interaction, i.e., laser wake field and coherent plasma wave. (author)

Radiation and impurity measurements in FRX-C/T

International Nuclear Information System (INIS)

Chrien, R.E.; McKenna, K.F.; Rej, D.J.; Tuszewski, M.

1984-01-01

Translation of Field-Reversed Configurations (FRCs) in the FRX-C/T device has provided better diagnostic access for radiation measurements. It is observed that radiated power accounts for 7 +- 2% of the total power losses, indicating that thermal conduction accounts for about half of the losses. It was determined through impurity seeding experiments that the oxygen fraction is 0.6 +- 0.2% and that oxygen can account for most of the radiated power

Third harmonic generation of high power far infrared radiation in semiconductors

Energy Technology Data Exchange (ETDEWEB)

Urban, M [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

1996-04-01

We investigated the third harmonic generation of high power infrared radiation in doped semiconductors with emphasis on the conversion efficiency. The third harmonic generation effect is based on the nonlinear response of the conduction band electrons in the semiconductor with respect to the electric field of the incident electromagnetic wave. Because this work is directed towards a proposed application in fusion plasma diagnostics, the experimental requirements for the radiation source at the fundamental frequency are roughly given as follows: a wavelength of the radiation at the fundamental frequency in the order of 1 mm and an incident power greater than 1 MW. The most important experiments of this work were performed using the high power far infrared laser of the CRPP. With this laser a new laser line was discovered, which fits exactly the source specifications given above: the wavelength is 676 {mu}m and the maximum power is up to 2 MW. Additional experiments were carried out using a 496 {mu}m laser and a 140 GHz (2.1 mm) gyrotron. The main experimental progress with respect to previous work in this field is, in addition to the use of a very high power laser, the possibility of an absolute calibration of the detectors for the far infrared radiation and the availability of a new type of detector with a very fast response. This detector made it possible to measure the power at the fundamental as well as the third harmonic frequency with full temporal resolution of the fluctuations during the laser pulse. Therefore the power dependence of the third harmonic generation efficiency could be measured directly. The materials investigated were InSb as an example of a narrow gap semiconductor and Si as standard material. The main results are: narrow gap semiconductors indeed have a highly nonlinear electronic response, but the narrow band gap leads at the same time to a low power threshold for internal breakdown, which is due to impact ionization. figs., tabs., refs.

Third harmonic generation of high power far infrared radiation in semiconductors

International Nuclear Information System (INIS)

Urban, M.

1996-04-01

In this work we investigated the third harmonic generation of high power infrared radiation in doped semiconductors with emphasis on the conversion efficiency. The third harmonic generation effect is based on the nonlinear response of the conduction band electrons in the semiconductor with respect to the electric field of the incident electromagnetic wave. Because this work is directed towards a proposed application in fusion plasma diagnostics, the experimental requirements for the radiation source at the fundamental frequency are roughly given as follows: a wavelength of the radiation at the fundamental frequency in the order of 1 mm and an incident power greater than 1 MW. The most important experiments of this work were performed using the high power far infrared laser of the CRPP. With this laser a new laser line was discovered, which fits exactly the source specifications given above: the wavelength is 676 μm and the maximum power is up to 2 MW. Additional experiments were carried out using a 496 μm laser and a 140 GHz (2.1 mm) gyrotron. The main experimental progress with respect to previous work in this field is, in addition to the use of a very high power laser, the possibility of an absolute calibration of the detectors for the far infrared radiation and the availability of a new type of detector with a very fast response. This detector made it possible to measure the power at the fundamental as well as the third harmonic frequency with full temporal resolution of the fluctuations during the laser pulse. Therefore the power dependence of the third harmonic generation efficiency could be measured directly. The materials investigated were InSb as an example of a narrow gap semiconductor and Si as standard material. The main results are: narrow gap semiconductors indeed have a highly nonlinear electronic response, but the narrow band gap leads at the same time to a low power threshold for internal breakdown, which is due to impact ionization. (author) figs

Controlling total spot power from holographic laser by superimposing a binary phase grating.

Science.gov (United States)

Liu, Xiang; Zhang, Jian; Gan, Yu; Wu, Liying

2011-04-25

By superimposing a tunable binary phase grating with a conventional computer-generated hologram, the total power of multiple holographic 3D spots can be easily controlled by changing the phase depth of grating with high accuracy to a random power value for real-time optical manipulation without extra power loss. Simulation and experiment results indicate that a resolution of 0.002 can be achieved at a lower time cost for normalized total spot power.

Characteristics of radiated power for various TFTR [Tokamak Fusion Test Reactor] regimes

International Nuclear Information System (INIS)

Bush, C.E.; Schivell, J.; McNeill, D.H.

1988-04-01

Power loss studies were carried out to determine the impurity radiation and energy transport characteristics of various TFTR operation and confinement regimes including L-Mode, detached plasma, co-only neutral beam injection (energetic ion regime), and the enhanced confinement (''supershot'') regime. Combined bolometric, spectroscopic, and infrared photometry measurements provide a picture of impurity behavior and power accounting in TFTR. The purpose of this paper is to make a survey of the various regimes with the aim of determining the radiated power signatures of each. 10 refs., 6 figs., 1 tab

Use of radiation and radiation practices 1994. Events and statistics

Energy Technology Data Exchange (ETDEWEB)

Havukainen, R. [ed.

1995-05-01

In Finland, there were 1,745 valid safety licences for the use of radiation at the end of 1994. In addition, 2,050 sites were included in the compulsory registration for dental x-ray diagnostics. The register of the Finnish Centre for Radiation and Nuclear Safety listed 12,794 radiation sources and 316 radionuclide laboratories. The import of radioactive substances amounted to 4.6x10{sup 15} Bq and export to 2.2x10{sup 13} Bq. A total of 1.4x10{sup 13} Bq of short-lived radionuclides were produced in Finland. Workers monitored for radiation exposure included 11,147 employees on 1,294 work sites. Of these, 27% received an annual dose exceeding the recording threshold. The total dose recorded in the dose register (sum of personal dosemeter readings) was 75 man Sv in 1994, nuclear power plant employees accounting for 70% of this total. The annual dosemeter reading of ten medical doctors (radiologists, international radiologists and cardiologists) and five nuclear power plant employees was equal to or in excess of 20 mSv. Effective dose, however, did not exceed the dose limit of 50 mSv established for a one-year monitoring period.

Study of the fluctuations of the partial and total radiative widths by neutron capture resonance method; Etude des fluctuations des largeurs radiatives partielles et totales par la capture des neutrons de resonance

Energy Technology Data Exchange (ETDEWEB)

Huynh, V.D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-06-01

Radiative capture experiments by neutron time-of-flight methods have been made for following studies: distribution of partial radiative widths, effects of correlation between different radiative transitions, fluctuations of total radiative widths {gamma}{sub {gamma}} from resonance to resonance, variation of {gamma}{sub {gamma}} with number of mass and the search for the existence of potential capture. Also, some other experiments with the use of neutron capture gamma-rays spectra have been investigated. (author) [French] Par la capture des neutrons de resonance dont les energies sont selectionnees a l'aide de la technique du temps de vol, differents types d'experiences ont ete realisees concernant les etudes des distributions des largeurs radiatives partielles, des effets de correlation entre differentes voies de desexcitation, de la fluctuation des largeurs radiatives totales {gamma}{sub {gamma}} de resonance a resonance, de la variation de la quantite {gamma}{sub {gamma}} en fonction du nombre de masse et de la mise en evidence de l'existence du processus de capture potentielle. Quelques autres applications de l'emploi du spectre de rayons gamma ont egalement ete presentees. (auteur)

Ganoderma lucidum total triterpenes prevent γ-radiation induced oxidative stress in Swiss albino mice in vivo.

Science.gov (United States)

Smina, T P; Joseph, Jini; Janardhanan, K K

2016-11-01

The in vivo radio-protective effect of total triterpenes isolated from Ganoderma lucidum (Fr.) P. Karst was evaluated using Swiss albino mice, by pre-treatment with total triterpenes for 14 days, followed by a whole body exposure to γ-radiation. The activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and the level of reduced glutathione (GSH) were analysed in liver and brain homogenates. The extent of lipid and protein peroxidation was also estimated in liver and brain homogenates after irradiation. Protection of radiation-induced DNA strand breaks in peripheral blood lymphocytes and bone marrow cells was assessed using the comet assay. Total triterpenes were highly effective in reducing the levels of lipid peroxidation and protein oxidation to near normal values in both liver and brain tissues. Total triterpenes, when administered in vivo, were also found to be successful in restoring the antioxidant enzyme activities and GSH level in liver and brain of irradiated mice. Administration of total triterpenes, prior to radiation exposure, significantly decreased the DNA strand breaks. The results of the present study thus revealed the potential therapeutic use of Ganoderma total triterpenes as an adjuvant in radiation therapy.

Variation of Neutron Moderating Power on HDPE by Gamma Radiation

International Nuclear Information System (INIS)

Park, Kwang June; Ju, June Sik; Kang, Hee Young; Shin, Hee Sung; Kim, Ho Dong

2009-01-01

High density polyethylene (HDPE) is degraded due to a radiation-induced oxidation when it is used as a neutron moderator in a neutron counter for a nuclear material accounting of spent fuels. The HDPE exposed to the gamma-ray emitted from the fission products in a spent nuclear fuel results in a radiation-induced degradation which changes its original molecular structure to others. So a neutron moderating power variation of HDPE, irradiated by a gamma radiation, was investigated in this work. Five HDPE moderator structures were exposed to the gamma radiation emitted from a 60 Co source to a level of 10 5 -10 9 rad to compare their post-irradiation properties. As a result of the neutron measurement test with 5 irradiated HDPE structures and a neutron measuring system, it was confirmed that the neutron moderating power for the 105 rad irradiated HDPE moderator revealed the largest decrease when the un-irradiated pure one was used as a reference. It implies that a neutron moderating power variation of HDPE is not directly proportional to the integrated gamma dose rate. To clarify the cause of these changes, some techniques such as a FTIR, an element analysis and a densitometry were employed. As a result of these analyses, it was confirmed that the molecular structure of the gamma irradiated HDPEs had partially changed to others, and the contents of hydrogen and oxygen had varied during the process of a radiation-induced degradation. The mechanism of these changes cannot be explained in detail at present, and thus need further study

Radiation protection aspects of design for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

The IAEA's Statute authorizes the Agency to establish safety standards to protect health and minimize danger to life and property - standards which the IAEA must use in its own operations, and which a State can apply by means of its regulatory provisions for nuclear and radiation safety. A comprehensive body of safety standards under regular review, together with the IAEA's assistance in their application, has become a key element in a global safety regime. In the mid-1990s, a major overhaul of the IAEA's safety standards programme was initiated, with a revised oversight committee structure and a systematic approach to updating the entire corpus of standards. The new standards that have resulted are of a high calibre and reflect best practices in Member States. With the assistance of the Commission on Safety Standards, the IAEA is working to promote the global acceptance and use of its safety standards. Safety standards are only effective, however, if they are properly applied in practice. The IAEA's safety services - which range in scope from engineering safety, operational safety, and radiation, transport and waste safety to regulatory matters and safety culture in organizations - assist Member States in applying the standards and appraise their effectiveness. These safety services enable valuable insights to be shared and continue to urge all Member States to make use of them. Regulating nuclear and radiation safety is a national responsibility, and many Member States have decided to adopt the IAEA's safety standards for use in their national regulations. For the Contracting Parties to the various international safety conventions, IAEA standards provide a consistent, reliable means of ensuring the effective fulfilment of obligations under the conventions. The standards are also applied by designers, manufacturers and operators around the world to enhance nuclear and radiation safety in power generation, medicine, industry, agriculture, research and education

Substantiation of the radiation monitoring scope in the region of nuclear power plant location

Energy Technology Data Exchange (ETDEWEB)

Zykova, A S; Zhakov, Yu A; Yambrovskii, Ya M

1977-12-01

To provide radiation safety of the population in the region of nuclear power plant location, it is necessary to define the character and quantity of radiation monitoring. On the basis of radiation monitoring of effluents from operating nuclear power plants it is found that the effluents can be registered at a distance of 5-7 km from the plant. The quantity of sample analysis of the main enviromental objectives must provide an exact definition of the content of radioactive substances produced by radioactive fallouts and effluents from nuclear power plants.

Substantiation of the radiation monitoring scope in the region of nuclear power plant location

International Nuclear Information System (INIS)

Zykova, A.S.; Zhakov, Yu.A.; Jambrovskij, Ya.M.

1977-01-01

To provide radiation safety of the population in the region of nuclear power plant location, it is necessary to define the character and quantity of radiation monitoring. On the basis of radiation monitoring of flowouts from operating nuclear power plants it is found that the flowouts can be registered at a distance of 5-7 km from the plant. The quantity of sample analysis of the main enviromental objectives must provide an exact definition of the content of radioactive substances produced by radioactive fallouts and flowouts from nuclear power plants

Radiation exposure in German nuclear power plants

International Nuclear Information System (INIS)

Mueller, W.

1981-01-01

The individual and collective doses in German nuclear power stations have decreased remarkably since the beginning of the commercial nuclear power production. The paper discusses the influencing factors, that have caused this development and points out areas where improvements are possible in the future. Moreover the interaction between radiation protection practice and the relevant legal regulations is considered. Usually the recording of job related doses is regarded as the most direct access to possible improvements. Concluding, it is therefore demonstrated by some examples how the evaluation of such information has taken effect in practice. (orig.) [de

Study of total ionization dose effects in electronic devices

International Nuclear Information System (INIS)

Nidhin, T.S.; Bhattacharyya, Anindya; Gour, Aditya; Behera, R.P.; Jayanthi, T.

2018-01-01

Radiation effects in electronic devices are a major challenge in the dependable application developments of nuclear power plant instrumentation and control systems. The main radiation effects are total ionization dose (TID) effects, displacement damage dose (DDD) effects and single event effects (SEE). In this study, we are concentrating on TID effects in electronic devices. The focus of the study is mainly on SRAM based field programmable gate arrays (FPGA) along with that the devices of our interest are voltage regulators, flash memory and optocoupler. The experiments are conducted by exposing the devices to gamma radiation in power off condition and the degradation in the performances are analysed

Radiation risk perception by radiation professionals. Survey results just before the radiological accident at the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant

International Nuclear Information System (INIS)

Miura, Miwa; Hayashida, Rika; Takao, Hideaki; Matsuda, Naoki; Ono, Koji

2013-01-01

From October to December 2010, just before the radiological accident at the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant, 71 radiation professionals belonging to the radiation facilities in Japan were asked what they consider as a 'safe' dose of radiation for themselves, their spouse, parents, children, brothers and friends. Although the 'safe' dose varied widely from less than 1 mSv/y to higher than 100 mSv/y, the average dose was 35.6 mSv/y that was around the middle point between the exposure dose limits for annual average (20 mSv/y) and for any single year (50 mSv/y). Similar results were obtained from another surveys for the members of Japan Radioisotope Association (36.9 mSv/y) and for the Oita Prefectural Hospital (36.8 mSv/y). Among the family members and friends, the minimum average 'safe' dose was 8.5 mSv/y for children, to whom 50% of responders claimed the 'safe' dose less than 1 mSv. Gender, age and specialty of the responder also affected the 'safe' dose. These findings suggest that the perception of radiation risk varies widely and that the legal exposure dose limit derived from the regulatory science may act as an anchor of safety even in radiation professionals. The different level of risk perception for different target groups in radiation professionals appears similar to those in non-professional whole population. The gap between these characteristics of real radiation professionals and the generally accepted picture of radiation professionals might take a part in a state of confusion after the radiological accident. (author)

Total and available metal contents in sediments by synchrotron radiation total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Moreira, Silvana; Sobrinho, Gilmar A.; Jesus, Edgar F.O. de; Lopes, Ricardo T.

2002-01-01

In this work the total and available contents of Al, Si, Cl, K, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Ba, Ce and Pb in sediments from river Atibaia were determined by Synchrotron Radiation Total Reflection X-Ray Fluorescence technique. The detection limits for K series varies from 200 ng.mL -1 for Al to 2 ng.mL -1 for Zn while for L series the value varies from 20 ng.mL -1 for Ba to 10 ng.mL -1 for Pb. The samples were submitted to two different processes, in order to obtain the total and biological available metal contents. The information about metal content is a important parameter for a correct evaluation about the hydrologic cycle in Piracicaba basin. All the measure were carried out at the National Synchrotron Light Laboratory, Campinas, SP, Brazil, using a white beam for excitation. (author)

High power beam profile monitor with optical transition radiation

International Nuclear Information System (INIS)

Denard, J.C.; Piot, P.; Capek, K.; Feldl, E.

1997-01-01

A simple monitor has been built to measure the profile of the high power beam (800 kW) delivered by the CEBAF accelerator at Jefferson Lab. The monitor uses the optical part of the forward transition radiation emitted from a thin carbon foil. The small beam size to be measured, about 100 μm, is challenging not only for the power density involved but also for the resolution the instrument must achieve. An important part of the beam instrumentation community believes the radiation being emitted into a cone of characteristic angle 1/γ is originated from a region of transverse dimension roughly λγ; thus the apparent size of the source of transition radiation would become very large for highly relativistic particles. This monitor measures 100 μm beam sizes that are much smaller than the 3.2 mm λγ limit; it confirms the statement of Rule and Fiorito that optical transition radiation can be used to image small beams at high energy. The present paper describes the instrument and its performance. The authors tested the foil in, up to 180 μA of CW beam without causing noticeable beam loss, even at 800 MeV, the lowest CEBAF energy

Occupational radiation exposure at commercial nuclear power reactors and other facilities, 1989

International Nuclear Information System (INIS)

Raddatz, C.T.

1992-04-01

This report summarizes the occupational radiation exposure information that has been reported to the NRC's Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC 1 licensees during the years 1969 through 1989. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10 CFR 20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC 1 licensed facilities were obtained from reports submitted pursuant to 10 CFR 20.408. The 1989 annual reports submitted by about 448 licensees indicated that approximately 216,294 individuals were monitored 111,000 of whom were monitored by nuclear power facilities. They incurred an average individual does of 0.18 rem (cSv) and an average measurable dose of 0.36 (cSv). Termination radiation exposure reports were analyzed to reveal that about 113,535 individuals completed their employment with one or more of the 448 covered licensees during 1989. Some 76,561 of these individuals terminated from power reactor facilities, and about 10, 344 of them were considered to be transient workers who received an average dose of 0.64 rem (cSv)

Occupational radiation exposure at commercial nuclear power reactors and other facilities, 1988

International Nuclear Information System (INIS)

Raddatz, C.T.

1991-07-01

This report summarizes the occupational radiation exposure information that has been reported to the NRC's Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC licensees during the years 1969 through 1988. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10 CFR 20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC licensed facilities were obtained from reports submitted pursuant to 10 CFR 20.408. The 1988 annual reports submitted by about 429 licensees indicated that approximately 220,048 individuals were monitored, 113,00 of whom were monitored by nuclear power facilities. They incurred an average individual dose of 0.20 rem (cSv) and an average measurable dose of 0.41 (cSv). Termination radiation exposure reports were analyzed to reveal that about 113,072 individuals completed their employment with one or more of the 429 covered licensees during 1988. Some 80,211 of these individuals terminated from power reactor facilities, and about 8,760 of them were considered to be transient workers who received an average dose of 0.27 rem (cSv). 17 refs., 11 figs., 29 tabs

Occupational radiation exposure at commercial nuclear power reactors and other facilities, 1991

International Nuclear Information System (INIS)

Raddatz, C.T.

1993-07-01

This report summarizes the occupational radiation exposure information that has been reported to the NRC's Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC licensees during the years 1969 through 1991. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10 CFR 20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC licensed facilities were obtained from reports submitted pursuant to 10 CFR 20.408. The 1991 annual reports submitted by about 436 licensees indicated that approximately 206,732 individuals were monitored, 182,334 of whom were monitored by nuclear power facilities. They incurred an average individual dose of 0.15 rem (cSv) and an average measurable dose of about 0.31 (cSv). Termination radiation exposure reports were analyzed to reveal that about 96,231 individuals completed their employment with one or more of the 436 covered licensees during 1991. Some 68,115 of these individuals terminated from power reactor facilities, and about 7,763 of them were considered to be transient workers who received an average dose of 0.52 rem (cSv)

The use of total detriment in radiation protection and its potential extension to other hazards

International Nuclear Information System (INIS)

Johnson, J.R.; Stansbury, P.S.; Selby, J.M.

1991-10-01

Before publication of the 1977 recommendations of the International Commission on Radiological Protection (ICRP), radiation protection standards were based on dose limits to single organs. These dose limits were only loosely linked to the expected effects in the first two generations from gonadal doses and to the risk of fatal cancer from doses to specific organs. In 1977, the ICRP recommended the use of the ''effective dose equivalent (EDE),'' which is a method of summing the doses (weighted with relative risk coefficients) to all organs and tissues, and recommended an annual limit for EDE. Since the 1977 recommendations were published, a ''total risk'' or total detriment approach has been extended to include nonfatal cancers and genetic effects for all subsequent generations, i.e., the total health detriment from low doses of ionizing radiation. This paper discusses the development of this total health detriment from ionizing radiation exposures, and explores potential methods for using it with other hazards (such as exposures to other physical agents, hazardous chemicals, and fatal and nonfatal accidents) in calculating the total detriment to a worker

Synchrotron radiation total reflection for rainwater analysis

International Nuclear Information System (INIS)

Simabuco, Silvana M.; Matsumoto, Edson

1999-01-01

Total reflection X-ray fluorescence analysis excited with synchrotron radiation (SR-TXRF) has been used for rainwater trace element analysis. The samples were collected in four different sites at Campinas City, SP. Standard solutions with gallium as internal standard were prepared for the calibration system. Rainwater samples of 10 μl were putted onto Perspex reflector disk, dried on vacuum and analyzed for 100 s measuring time. The detection limits obtained for K-shell varied from 29 ng.ml -1 for sulfur to 1.3 ng.ml -1 for zinc and copper, while for L-shell the values were 4.5 ng.ml -1 for mercury and 7.0 ng.ml -1 for lead. (author)

Clinical Usefulness of serum total cholesterol as an index of hypothyroidism in patients after cervical radiation

International Nuclear Information System (INIS)

Iguma, Yoko; Iwai, Chikako; Okuyama, Masako; Futami, Takahiro; Inui, Ken-ichi; Asato, Ryo

2003-01-01

Cervical radiation therapy is often applied to patients with head and neck cancers because radiation has a high sensitivity to these cancers and permits the preservation of functions and physical form. However, it has been shown that various complications can result from radiation therapy. We have encountered some patients who showed hypercholesterolemia resulting from cervical radiation. Therefore, we have paid close attention to the relationship between hypercholesterolemia after cervical radiation and hypothyroidism. Thyroid hormone tests in these patients with hypercholesterolemia after cervical radiation showed high thyroid stimulating hormone (TSH) and low free thyroxine (fT 4 ), indicating the presence of hypothyroidism. After administration of levothyroxine Na, their fT 4 levels increased and both TSH levels and serum total cholesterol levels decreased. In conclusion, in patients who have received cervical radiation, we recommend monitoring serum total cholesterol periodically to detect hypothyroidism easily before the appearance of its symptoms. (author)

Clinical Usefulness of serum total cholesterol as an index of hypothyroidism in patients after cervical radiation

Energy Technology Data Exchange (ETDEWEB)

Iguma, Yoko; Iwai, Chikako; Okuyama, Masako; Futami, Takahiro; Inui, Ken-ichi [Kyoto Univ. (Japan). Hospital; Asato, Ryo [Kyoto Univ. (Japan). Graduate School of Medicine

2003-02-01

Cervical radiation therapy is often applied to patients with head and neck cancers because radiation has a high sensitivity to these cancers and permits the preservation of functions and physical form. However, it has been shown that various complications can result from radiation therapy. We have encountered some patients who showed hypercholesterolemia resulting from cervical radiation. Therefore, we have paid close attention to the relationship between hypercholesterolemia after cervical radiation and hypothyroidism. Thyroid hormone tests in these patients with hypercholesterolemia after cervical radiation showed high thyroid stimulating hormone (TSH) and low free thyroxine (fT{sub 4}), indicating the presence of hypothyroidism. After administration of levothyroxine Na, their fT{sub 4} levels increased and both TSH levels and serum total cholesterol levels decreased. In conclusion, in patients who have received cervical radiation, we recommend monitoring serum total cholesterol periodically to detect hypothyroidism easily before the appearance of its symptoms. (author)

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

Efficient power combiner for THz radiation

Energy Technology Data Exchange (ETDEWEB)

Seidfaraji, Hamide, E-mail: hsfaraji@unm.edu; Fuks, Mikhail I.; Christodoulou, Christos; Schamiloglu, Edl [Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, 87131-0001 (United States)

2016-08-15

Most dangerous explosive materials, both toxic and radioactive, contain nitrogen salts with resonant absorption lines in the frequency range 0.3-10 THz. Therefore, there has been growing interest in remotely detecting such materials by observing the spectrum of reflected signals when the suspicious material is interrogated by THz radiation. Practical portable THz sources available today generate only 20–40 mW output power. This power level is too low to interrogate suspicious material from a safe distance, especially if the material is concealed. Hence, there is a need for sources that can provide greater power in the THz spectrum. Generating and extracting high output power from THz sources is complicated and inefficient. The efficiency of vacuum electronic microwave sources is very low when scaled to the THz range and THz sources based on scaling down semiconductor laser sources have low efficiency as well, resulting in the well known “THz gap.” The reason for such low efficiencies for both source types is material losses in the THz band. In this article an efficient power combiner is described that is based on scaling to higher frequencies a microwave combiner that increases the output power in the THz range of interest in simulation studies. The proposed power combiner not only combines the THz power output from several sources, but can also form a Gaussian wavebeam output. A minimum conversion efficiency of 89% with cophased inputs in a lossy copper power combiner and maximum efficiency of 100% in a Perfect Electric Conductor (PEC)-made power combiner were achieved in simulations. Also, it is shown that the TE{sub 01} output mode is a reasonable option for THz applications due to the fact that conductive loss decreases for this mode as frequency increases.

Efficient power combiner for THz radiation

Directory of Open Access Journals (Sweden)

Hamide Seidfaraji

2016-08-01

Full Text Available Most dangerous explosive materials, both toxic and radioactive, contain nitrogen salts with resonant absorption lines in the frequency range 0.3-10 THz. Therefore, there has been growing interest in remotely detecting such materials by observing the spectrum of reflected signals when the suspicious material is interrogated by THz radiation. Practical portable THz sources available today generate only 20–40 mW output power. This power level is too low to interrogate suspicious material from a safe distance, especially if the material is concealed. Hence, there is a need for sources that can provide greater power in the THz spectrum. Generating and extracting high output power from THz sources is complicated and inefficient. The efficiency of vacuum electronic microwave sources is very low when scaled to the THz range and THz sources based on scaling down semiconductor laser sources have low efficiency as well, resulting in the well known “THz gap.” The reason for such low efficiencies for both source types is material losses in the THz band. In this article an efficient power combiner is described that is based on scaling to higher frequencies a microwave combiner that increases the output power in the THz range of interest in simulation studies. The proposed power combiner not only combines the THz power output from several sources, but can also form a Gaussian wavebeam output. A minimum conversion efficiency of 89% with cophased inputs in a lossy copper power combiner and maximum efficiency of 100% in a Perfect Electric Conductor (PEC-made power combiner were achieved in simulations. Also, it is shown that the TE01 output mode is a reasonable option for THz applications due to the fact that conductive loss decreases for this mode as frequency increases.

Is natural background or radiation from nuclear power plants leukemogenic?

International Nuclear Information System (INIS)

Cronkite, E.P.

1989-01-01

The objective in this review is to provide some facts about normal hemopoietic cell proliferation relevant to leukemogenesis, physical, chemical, and biological facts about radiation effects with the hope that each person will be able to decide for themselves whether background radiation or emissions from nuclear power plants and facilities significantly add to the spontaneous leukemia incidence. 23 refs., 1 tab

Status and problems of radiation education in Taiwan

International Nuclear Information System (INIS)

Huang Chin-Wang

1999-01-01

In Taiwan, there are few numbers of radiation education, courses this fact makes an impression of insufficiency. This matter is thinkable to be an important problem. There are sets of atomic power stations and 6 atomic reactors are now operating. The electric power production is about 50144 MW, which comprises 20 % of total electric power in the country. The knowledge for the related to the radiation is not diffuse and there is only frightened impression. The radiation education should be spread to the ordinary citizen, and essential qualities a risk of the radiation should be instructed sufficiently. The radiation literacy of the ordinary citizen is needed to raise the level. (author)

Clear-Sky Probability for the August 21, 2017, Total Solar Eclipse Using the NREL National Solar Radiation Database

Energy Technology Data Exchange (ETDEWEB)

Habte, Aron M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Roberts, Billy J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kutchenreiter, Mark C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wilcox, Steve [Solar Resource Solutions, LLC, Lakewood, CO (United States); Stoffel, Tom [Solar Resource Solutions, LLC, Lakewood, CO (United States)

2017-07-21

The National Renewable Energy Laboratory (NREL) and collaborators have created a clear-sky probability analysis to help guide viewers of the August 21, 2017, total solar eclipse, the first continent-spanning eclipse in nearly 100 years in the United States. Using cloud and solar data from NREL's National Solar Radiation Database (NSRDB), the analysis provides cloudless sky probabilities specific to the date and time of the eclipse. Although this paper is not intended to be an eclipse weather forecast, the detailed maps can help guide eclipse enthusiasts to likely optimal viewing locations. Additionally, high-resolution data are presented for the centerline of the path of totality, representing the likelihood for cloudless skies and atmospheric clarity. The NSRDB provides industry, academia, and other stakeholders with high-resolution solar irradiance data to support feasibility analyses for photovoltaic and concentrating solar power generation projects.

The Performance Evaluation of Overall Heat Transfer and Pumping Power of γ-Al2O3/water Nanofluid as Coolant in Automotive Diesel Engine Radiator

Directory of Open Access Journals (Sweden)

Navid Bozorgan

2013-05-01

Full Text Available The efficiency of γ-Al2O3/water nanofluid as coolant is investigated in the present study. γ-Al2O3 nanoparticles with diameters of 20 nm dispersed in water with volume concentrations up 2% are selected and their performance in a radiator of Chevrolet Suburban diesel engine under turbulent flow conditions are numerically studied. The performance of an automobile radiator is a function of overall heat transfer coefficient and total heat transfer area. The heat transfer relations between nanofluid and airflow have been investigated to evaluate the overall heat transfer and the pumping power of γ-Al2O3/water nanofluid in the radiator with a given heat exchange capacity. In the present paper, the effects of the automotive speed and Reynolds number of the nanofluid in the different volume concentrations on the radiator performance are also investigated. As an example, the results show that for 2% γ-Al2O3 nanoparticles in water with Renf=6000 in the radiator while the automotive speed is 50 mph, the overall heat transfer coefficient and pumping power are approximately 11.11% and 29.17% more than that of water for given conditions, respectively. These results confirm that γ-Al2O3/water nanofluid offers higher overall heat transfer performance than water and can be reduced the total heat transfer area of the radiator.

Measurement of radiation power from the JIPP T-IIU tokamak plasma

International Nuclear Information System (INIS)

Ogawa, Isamu.

1987-04-01

Characteristics of a pyroelectric detector, a metal-film bolometer and a thermistor are investigated in order to attain high reliability of the bolometric measurement. The spurious signal which appears on a pyroelectric detector is efficiently eliminated by setting a mask close to the detector, which has a function of avoiding the direct incidence of photons on its electrode. This is verified with the consistency of integrated value of the signal. The detector is calibrated with a HeNe laser taking the reflection on the detector surface into account. No temporal change has been seen on the sensitivity of the detector calibrated by this method. We also developed a thin metal-film bolometer with high sensitivity (12.9 Ω/mJ), high time response (3 μs) and well defined thermal characteristics. The calibration of this detector was performed by supplying a bias current through its resistor. We constructed a bolometric system with high time response and high spatial resolution, which consisted of twelve pyroelectric detectors and a metal-film bolometer. The radiation power measured with the pyroelectric detector agrees with that measured with the calibrated metal-film bolometer within 10 %. Spectroscopic and bolometric measurements with spatial and temporal resolution show that large radiation loss brings about the decrease in electron and ion temperatures and plasma energy. Carbon limiters have an effect to suppress the radiation power for ohmic plasma, but are insufficient for ICRF heated plasma. The main contribution to radiation power may be attributed to Fe impurity released from the ICRF antennae, the Faraday shield and vacuum vessel. By making carbonization of the wall and in-vessel components, the Fe impurity is suppressed to a low level (n Fe /n e ∼ 0.04 %) and the radiation power is reduced to P rad /(P OH + P rf ) ∼ 20 % and emissivity throughout the plasma region is reduced. (author)

Knowledge of the inhabitants of Belarus on the radiation and power problems

International Nuclear Information System (INIS)

Vastchenko, S. V.

2000-01-01

The anonymous questionnaire of the inhabitants living in various regions of Belarus and having different age and level of education ha been done. The poll has been carried out aiming at definition of a general radiation erudition, as well as revealing the knowledge of the population about the effect of power stations (nuclear and thermal) on the environment and the health of a human being. The analysis of answers shows that people have a rather vague idea in the sphere considered. The analysis of the questionnaires shows that women are informed worse than men about the problems on radiation subjects. The investigation carried out has shown what problems on nuclear power (and radiation safety) should be given the more serious consideration when working with population, especially with women's audience, in order to raise the level of accepting nuclear power as the necessary source of energy. (author)

Radiation management and health management at the Chernobyl nuclear power plant

International Nuclear Information System (INIS)

Okazaki, Ryuji; Kubo, Tatsuhiko; Tateishi, Seiichiro

2014-01-01

This paper describes the measures taken by the Chernobyl nuclear power plant since the accident in April 1986 to date, compares them with the situation of the current Fukushima nuclear accident, and introduces the contents of the authors' visit and coverage in October 2013, including the report of radiation damage. At the Chernobyl site, a new sarcophagus is under construction since 2012. The health care of the workers working at the new and old sarcophaguses of the Chernobyl nuclear power plant is carried out at a national level of Ukraine, which is an important management for decommissioning work. Health diagnosis is also applied to the workers in the new sarcophagus, and radiation-related disease is not reported at present. The number of the persons who died from acute radiation exposure diseases after the accident was 28. It was reported that chronic lymphocytic leukemia (CLL) appeared significantly when the radiation exceeded 100 mSv. The workers who wish to work at the Chernobyl nuclear power plant must pass the test and obtain national qualifications, and then they are able to work for the first time. In the check-in medical control, about half of applicants were rejected. Workers who work at the new sarcophagus are subject to comprehensive health management under the Ukrainian law. There were 58 people who reached annual exposure dose limit of 20 mSv or more among 7,529 people, the cause of which may be the work at the areas of high radiation dose. Even in Fukushima, it is important to perform high quality management based on centralized medical examination, and to further analyze the effects of low-dose exposure to radiation. (A.O.)

Very high power THz radiation at Jefferson Lab

International Nuclear Information System (INIS)

Carr, G.L.; Martin, Michael C.; McKinney, Wayne R.; Jordan, K.; Neil, George R.; Williams, G.P.

2002-01-01

We report the production of high power (20 watts average, ∼;1 Megawatt peak) broadband THz light based on coherent emission from relativistic electrons. We describe the source, presenting theoretical calculations and their experimental verification. For clarity we compare this source with one based on ultrafast laser techniques, and in fact the radiation has qualities closely analogous to that produced by such sources, namely that it is spatially coherent, and comprises short duration pulses with transform-limited spectral content. In contrast to conventional THz radiation, however, the intensity is many orders of magnitude greater due to the relativistic enhancement

Prospects for using implanted systems of assisted circulation and artificial heart with a radioisotope power source (biomedical, thermal, and radiation aspects)

Energy Technology Data Exchange (ETDEWEB)

Kiselev, I M; Dubrovskii, G P; Mosidze, T G; Bazhanov, A I.U.

1983-02-01

The capacity of dogs to diffuse heat (up to 50 W) from an artificial heart and to tolerate prolonged intracorporeal ionizing radiation from a radioisotope power source (/sup 238/Pu) was investigated, using electrical models of vascular blood heat exchangers that permit reproduction of elimination and heat transmission in autonomous systems. It was shown that up to 50 W can be discharged at temperatures of the wall-blood interface that do not exceed 43 degrees C. Clotting indexes, concentration of total protein, hemolysis, and serum enzyme activity during 1-1.5 months of heating remained within physiologically normal limits. A specific power load of up to 1.5 W/kg at ambient temperatures of 18-20 degrees C revealed no evidence of changes in heat production. By measuring the distribution of power of the dose absorbed around a 45-W plutonium source it was possible to estimate dose loads on critical organs and to assess overall risk of death from malignant tumors induced by radiation over a 10-year period: 6-12% for males and 8-14% for females. It is not very probable that use of the artificial heart with a radioisotope power source will be limited by thermal and radiational effects.

Low power consumption and high temperature durability for radiation sensor

International Nuclear Information System (INIS)

Matsumoto, Yoshinori; Ueno, Hiroto

2015-01-01

Low power consumption and high temperature operation are important in an environmental monitoring system. The power consumption of 3 mW is achieved for the radiation sensor using low voltage operational amplifier and comparator in the signal processing circuit. The leakage reverse current of photodiode causes the charge amplifier saturation over 50degC. High temperature durability was improved by optimizing the circuit configuration and the values of feedback resistance and capacitance in the charge amplifier. The pulse response of the radiation sensor was measured up to 55degC. The custom detection circuit was designed by 0.6 μm CMOS process at 5-V supply voltage. The operation temperature was improved up to 65degC. (author)

Radiation control system of nuclear power plants

International Nuclear Information System (INIS)

Kapisovsky, V.; Kosa, M.; Melichar, Z.; Moravek, J.; Jancik, O.

1977-01-01

The SYRAK system is being developed for in-service radiation control of the V-1 nuclear power plant. Its basic components are an EC 1010 computer, a CAMAC system and communication means. The in-service release of radionuclides is measured by fuel can failure detection, by monitoring rare gases in the coolant, by gamma spectrometric coolant monitoring and by iodine isotopes monitoring in stack disposal. (O.K.)

A Brief Review of Heavy-Ion Radiation Degradation and Failure of Silicon UMOS Power Transistors

Directory of Open Access Journals (Sweden)

Kenneth F. Galloway

2014-09-01

Full Text Available Silicon VDMOS power MOSFET technology is being supplanted by UMOS (or trench power MOSFET technology. Designers of spaceborne power electronics systems incorporating this newer power MOSFET technology need to be aware of several unique threats that this technology may encounter in space. Space radiation threats to UMOS power devices include vulnerabilities to SEB, SEGR, and microdose. There have been relatively few studies presented or published on the effects of radiation on this device technology. The S-O-A knowledge of UMOS power device degradation and failure under heavy-ion exposure is reviewed.

Some problems concerning the radiation protection in nuclear power stations

International Nuclear Information System (INIS)

Bozoky, L.

1977-01-01

The appearance and fast spreading of the nuclear power stations raised new and difficult questions in connection with the theoretical bases of radiation protection. The new standpoint of the International Commission on Radiological Protection is that both the workers at a pile and the inhabitants take less risk because of ionizing radiation than they usually take in everyday life. The maximum dose which can be permitted remained 5 rem/year for those who professionally deal with ionizing radiation and 0.5 rem/year for the groups in special situation. (V.N.)

Damage-Tolerant, Lightweight, High-Temperature Radiator for Nuclear Powered Spacecraft

Data.gov (United States)

National Aeronautics and Space Administration — Game-changing propulsion systems are often enabled by novel designs using advanced materials. Radiator performance dictates power output for nuclear electric...

Research on the method of establishing the total radiation meter calibration device

Science.gov (United States)

Gao, Jianqiang; Xia, Ming; Xia, Junwen; Zhang, Dong

2015-10-01

Pyranometer is an instrument used to measure the solar radiation, according to pyranometer differs as installation state, can be respectively measured total solar radiation, reflected radiation, or with the help of shading device for measuring scattering radiation. Pyranometer uses the principle of thermoelectric effect, inductive element adopts winding plating type multi junction thermopile, its surface is coated with black coating with high absorption rate. Hot junction in the induction surface, while the cold junction is located in the body, the cold and hot junction produce thermoelectric potential. In the linear range, the output signal is proportional to the solar irradiance. Traceability to national meteorological station, as the unit of the national legal metrology organizations, the responsibility is to transfer value of the sun and the earth radiation value about the national meteorological industry. Using the method of comparison, with indoor calibration of solar simulator, at the same location, standard pyranometer and measured pyranometer were alternately measured radiation irradiance, depending on the irradiation sensitivity standard pyranometer were calculated the radiation sensitivity of measured pyranometer. This paper is mainly about the design and calibration method of the pyranometer indoor device. The uncertainty of the calibration result is also evaluated.

Numerical simulation and experimental research of the integrated high-power LED radiator

Science.gov (United States)

Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

2017-01-01

The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

Non-Directional Radiation Spread Modeling and Non-Invasive Estimating the Radiation Scattering and Absorption Parameters in Biological Tissue

Directory of Open Access Journals (Sweden)

S. Yu. Makarov

2015-01-01

Full Text Available The article dwells on a development of new non-invasive measurement methods of optical parameters of biological tissues, which are responsible for the scattering and absorption of monochromatic radiation. It is known from the theory of radiation transfer [1] that for strongly scattering media, to which many biological tissues pertain, such parameters are parameters of diffusion approximation, as well as a scattering coefficient and an anisotropy parameter.Based on statistical modeling the paper examines a spread of non-directional radiation from a Lambert light beam with the natural polarization that illuminates a surface of the biological tissue. Statistical modeling is based on the Monte Carlo method [2]. Thus, to have the correct energy coefficient values of Fresnel reflection and transmission in simulation of such radiation by Monte Carlo method the author uses his finding that is a function of the statistical representation for the incidence of model photons [3]. The paper describes in detail a principle of fixing the power transmitted by the non-directional radiation into biological tissue [3], and the equations of a power balance in this case.Further, the paper describes the diffusion approximation of a radiation transfer theory, often used in simulation of radiation propagation in strongly scattering media and shows its application in case of fixing the power transmitted into the tissue. Thus, to represent an uneven power distribution is used an approximating expression in conditions of fixing a total input power. The paper reveals behavior peculiarities of solution on the surface of the biological tissue inside and outside of the incident beam. It is shown that the solution in the region outside of the incident beam (especially far away from it, essentially, depends neither on the particular power distribution across the surface, being a part of the tissue, nor on the refractive index of the biological tissue. It is determined only by

Soft X-ray radiation power characteristics of tungsten wire arrays on Yang accelerator

International Nuclear Information System (INIS)

Zhang Siqun; Ouyang Kai; Huang Xianbin; Dan Jiakun; Zhou Rongguo; Yang Liang

2013-01-01

A series of experiments were carried out to research the X-ray radiation characteristics of tungsten wire arrays on Yang accelerator. In those experiments, we charged the Marx generator of 60 kV, and the load current of 0.85-1.00 MA, the rise time of 75-90 ns (10%-90%). A soft X-ray scintillator powermeter which responded flatly to 50-1800 eV X-rays was used to measure the power of soft X-ray emitted from implosion plasma. In this paper, we present the measuring results of time-resolved soft X-ray radiation power, and discuss the radiation characteristics of implosion plasma by analyzing the correlations of soft X-ray radiant power and the diameter, length, wire number of the tungsten wire arrays. The optimizing wire array configuration parameters on Yang are as follows: 8 mm array diameter, 15 mm wire length, and 24 wire number. We also present the radiant power difference in radial and axial directions of the wire arrays. (authors)

IRSN's Position on Safety and Radiation Protection at Nuclear Power Plants in France, 2012

International Nuclear Information System (INIS)

2014-01-01

After working a year to consolidate the data, the annual report on the radiation protection and safety of nuclear power plants in France gives the IRSN's independent point of view on all progress and problems concerning safety and radiation protection encountered in the French nuclear power plant fleet in 2012. The first part of the report presents the main trends that emerge from IRSN's overall assessment of the radiation protection and safety performance of currently operating nuclear power plants for the year 2012. The year 2012 has witnessed an increase in the total number of significant events. However, IRSN notes the absence in 2012 of incidents with a potentially significant impact on nuclear power plant safety, the surrounding environment or nearby communities in a context of large-scale personnel renewal. This increase can mainly be explained by EDF's implementation of an improved nonconformance detection and handling procedure which led to the identification, in 2012, of various non-conformances presumably present for several years but previously undetected. With regard to radiation protection, IRSN notes that the effective dose received by the majority of exposed workers over a period of 12 consecutive months is below the annual public radiation dose limit. Faults may occur with nuclear power plant equipment or reactor monitoring systems. Given the standardisation of EDF nuclear power plant reactors, such faults may affect an entire reactor series or even the entire reactor fleet. A few examples deemed particularly significant by IRSN are presented in the second part of this report. French nuclear reactors are subject to modifications throughout their operating lives, particularly with a view to ensuring continuous safety improvement, this is the subject of the third part of the report. Most of these modifications are the result of studies conducted within the framework of ten-yearly safety reviews, leading to the definition and

Estimation of soft X-ray and EUV transition radiation power emitted from the MIRRORCLE-type tabletop synchrotron.

Science.gov (United States)

Toyosugi, N; Yamada, H; Minkov, D; Morita, M; Yamaguchi, T; Imai, S

2007-03-01

The tabletop synchrotron light sources MIRRORCLE-6X and MIRRORCLE-20SX, operating at electron energies E(el) = 6 MeV and E(el) = 20 MeV, respectively, can emit powerful transition radiation (TR) in the extreme ultraviolet (EUV) and the soft X-ray regions. To clarify the applicability of these soft X-ray and EUV sources, the total TR power has been determined. A TR experiment was performed using a 385 nm-thick Al foil target in MIRRORCLE-6X. The angular distribution of the emitted power was measured using a detector assembly based on an NE102 scintillator, an optical bundle and a photomultiplier. The maximal measured total TR power for MIRRORCLE-6X is P(max) approximately equal 2.95 mW at full power operation. Introduction of an analytical expression for the lifetime of the electron beam allows calculation of the emitted TR power by a tabletop synchrotron light source. Using the above measurement result, and the theoretically determined ratio between the TR power for MIRRORCLE-6X and MIRRORCLE-20SX, the total TR power for MIRRORCLE-20SX can be obtained. The one-foil TR target thickness is optimized for the 20 MeV electron energy. P(max) approximately equal 810 mW for MIRRORCLE-20SX is obtained with a single foil of 240 nm-thick Be target. The emitted bremsstrahlung is negligible with respect to the emitted TR for optimized TR targets. From a theoretically known TR spectrum it is concluded that MIRRORCLE-20SX can emit 150 mW of photons with E > 500 eV, which makes it applicable as a source for performing X-ray lithography. The average wavelength, \\overline\\lambda = 13.6 nm, of the TR emission of MIRRORCLE-20SX, with a 200 nm Al target, could provide of the order of 1 W EUV.

Radiation protection aspects in the design of nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2008-01-01

The IAEA's Statute authorizes the Agency to establish safety standards to protect health and minimize danger to life and property - standards which the IAEA must use in its own operations, and which a State can apply by means of its regulatory provisions for nuclear and radiation safety. A comprehensive body of safety standards under regular review, together with the IAEA's assistance in their application, has become a key element in a global safety regime. In the mid-1990s, a major overhaul of the IAEA's safety standards programme was initiated, with a revised oversight committee structure and a systematic approach to updating the entire corpus of standards. The new standards that have resulted are of a high calibre and reflect best practices in Member States. With the assistance of the Commission on Safety Standards, the IAEA is working to promote the global acceptance and use of its safety standards. Safety standards are only effective, however, if they are properly applied in practice. The IAEA's safety services - which range in scope from engineering safety, operational safety, and radiation, transport and waste safety to regulatory matters and safety culture in organizations - assist Member States in applying the standards and appraise their effectiveness. These safety services enable valuable insights to be shared and continue to urge all Member States to make use of them. Regulating nuclear and radiation safety is a national responsibility, and many Member States have decided to adopt the IAEA's safety standards for use in their national regulations. For the Contracting Parties to the various international safety conventions, IAEA standards provide a consistent, reliable means of ensuring the effective fulfilment of obligations under the conventions. The standards are also applied by designers, manufacturers and operators around the world to enhance nuclear and radiation safety in power generation, medicine, industry, agriculture, research and education

47 CFR 22.535 - Effective radiated power limits.

Science.gov (United States)

2010-10-01

... limits. The effective radiated power (ERP) of transmitters operating on the channels listed in § 22.531 must not exceed the limits in this section. (a) Maximum ERP. The ERP must not exceed the applicable limits in this paragraph under any circumstances. Frequency range (MHz) Maximum ERP (Watts) 35-36 600 43...

Radiation Mitigation and Power Optimization Design Tools for Reconfigurable Hardware in Orbit

Science.gov (United States)

French, Matthew; Graham, Paul; Wirthlin, Michael; Wang, Li; Larchev, Gregory

2005-01-01

The Reconfigurable Hardware in Orbit (RHinO)project is focused on creating a set of design tools that facilitate and automate design techniques for reconfigurable computing in space, using SRAM-based field-programmable-gate-array (FPGA) technology. In the second year of the project, design tools that leverage an established FPGA design environment have been created to visualize and analyze an FPGA circuit for radiation weaknesses and power inefficiencies. For radiation, a single event Upset (SEU) emulator, persistence analysis tool, and a half-latch removal tool for Xilinx/Virtex-II devices have been created. Research is underway on a persistence mitigation tool and multiple bit upsets (MBU) studies. For power, synthesis level dynamic power visualization and analysis tools have been completed. Power optimization tools are under development and preliminary test results are positive.

Effect of gamma radiation on total antioxidant capacity, total lipid concentration and shelf life of finger millet flour

International Nuclear Information System (INIS)

Lathika; Manupriya, B.R.; Shenoy, K.B.; Patil, S.L.; Somashekarappa, H.M.

2016-01-01

The present study is an attempt to study the impact of gamma radiation on the shelf life, total antioxidant capacity and total lipid concentration of finger millet (Eleusine coracana L.) flour. Finger millet flour was procured from market. Flour samples of 50 g were taken in triplicates in a polyethylene pouch, air sealed and subjected to gamma irradiation doses ranging from 0.25 to 10 kGy and stored in polyethylene bags and plastic containers for a period of 1 year. Within 24 hours of irradiation, the samples were tested for moisture (2 ± 0.2%), total antioxidant capacity (0.12 ± 0.010 mg) and lipid concentration (15 ± 0.4 mg)

Radiation practices 1996

International Nuclear Information System (INIS)

Havukainen, R.

1997-05-01

At the end of 1996, there were 1,762 valid safety licences in Finland for the use of radiation. In addition, there were 2,052 responsible parties for dental x-ray diagnostics. The registry of the Finnish Centre for Radiation and Nuclear Safety listed 13,360 radiation sources and 313 radionuclide laboratories. The import of radioactive substances amounted to 1.14 x 10 +16 Bq and export to 7.78 x 10 +13 Bq. A total of 4.02 x 10 +13 Bq of short-lived radionuclides were produced in Finland. There were 11,842 workers monitored for radiation exposure at 1,352 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of individual dosimeter readings) was 7.96 manSv in 1996, with nuclear power plant workers accounting for 69% of this total. The annual dosimeter reading of ten medical doctors (radiologists, interventional radiologists and cardiologists) and eight nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of dosimeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 242 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations where unusually high exposure to radiation was an unavoidable part of the task. Report was made of 12 incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Five of these cases occurred in radiotherapy, three in use of a radiation source in industry, three in transport of radiation sources and one in use of solarium appliances. Radiation-contaminated material was found in 17 shipments of scrap. (orig.)

Radiation practices 1996

Energy Technology Data Exchange (ETDEWEB)

Havukainen, R. [ed.

1997-05-01

At the end of 1996, there were 1,762 valid safety licences in Finland for the use of radiation. In addition, there were 2,052 responsible parties for dental x-ray diagnostics. The registry of the Finnish Centre for Radiation and Nuclear Safety listed 13,360 radiation sources and 313 radionuclide laboratories. The import of radioactive substances amounted to 1.14 x 10{sup +16} Bq and export to 7.78 x 10{sup +13} Bq. A total of 4.02 x 10{sup +13} Bq of short-lived radionuclides were produced in Finland. There were 11,842 workers monitored for radiation exposure at 1,352 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of individual dosimeter readings) was 7.96 manSv in 1996, with nuclear power plant workers accounting for 69% of this total. The annual dosimeter reading of ten medical doctors (radiologists, interventional radiologists and cardiologists) and eight nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of dosimeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 242 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations where unusually high exposure to radiation was an unavoidable part of the task. Report was made of 12 incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Five of these cases occurred in radiotherapy, three in use of a radiation source in industry, three in transport of radiation sources and one in use of solarium appliances. Radiation-contaminated material was found in 17 shipments of scrap. (orig.)

Effects of total dose of ionizing radiation on integrated circuits

Energy Technology Data Exchange (ETDEWEB)

Silveira, Marcilei A.G.; Cirne, K.H.; Gimenez, S.; Santos, R.B.B. [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil); Added, N.; Barbosa, M.D.L.; Medina, N.H.; Tabacniks, M.H. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Lima, J.A. de; Seixas Junior, L.E.; Melo, W. [Centro de Tecnologia da Informacao Paulo Archer, Sao Paulo, SP (Brazil)

2011-07-01

Full text: The study of ionizing radiation effects on materials used in electronic devices is of great relevance for the progress of global technological development and, particularly, it is a necessity in some strategic areas in Brazil. Electronic circuits are strongly influenced by radiation and the need for IC's featuring radiation hardness is largely growing to meet the stringent environment in space electronics. On the other hand, aerospace agencies are encouraging both scientific community and semiconductors industry to develop hardened-by-design components using standard manufacturing processes to achieve maximum performance, while significantly reducing costs. To understand the physical phenomena responsible for changes in devices exposed to ionizing radiation several kinds of radiation should then be considered, among them alpha particles, protons, gamma and X-rays. Radiation effects on the integrated circuits are usually divided into two categories: total ionizing dose (TID), a cumulative dose that shifts the threshold voltage and increases transistor's off-state current; single events effects (SEE), a transient effect which can deposit charge directly into the device and disturb the properties of electronic circuits. TID is one of the most common effects and may generate degradation in some parameters of the CMOS electronic devices, such as the threshold voltage oscillation, increase of the sub-threshold slope and increase of the off-state current. The effects of ionizing radiation are the creation of electron-hole pairs in the oxide layer changing operation mode parameters of the electronic device. Indirectly, there will be also changes in the device due to the formation of secondary electrons from the interaction of electromagnetic radiation with the material, since the charge carriers can be trapped both in the oxide layer and in the interface with the oxide. In this work we have investigated the behavior of MOSFET devices fabricated with

Lunar surface fission power supplies: Radiation issues

International Nuclear Information System (INIS)

Houts, M.G.; Lee, S.K.

1994-01-01

A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to these seen in free space. For a well designed shield, the additional mass required to be brought fro earth should be less than 1000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield

Lunar surface fission power supplies: Radiation issues

International Nuclear Information System (INIS)

Houts, M.G.; Lee, S.K.

1994-01-01

A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to those seen in free space. For a well designed shield, the additional mass required to be brought from earth should be less than 1,000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield

The new development of radiation processing in China

International Nuclear Information System (INIS)

Chen Dianhua

1998-12-01

China Isotope and Radiation Association (CIRA) investigated the status of radiation processing in China's mainland. There are 45 accelerators each with beam power over 5 kW, the total beam power is 2005 kW. There are 48 γ facilities each with designed capacity over 1.11 x 10 4 TBq (0.3 million curies) and other 75 units with designed capacity less than 1.11 x 10 4 TBq. The total loaded capacity is 4.63 x 10 5 TBq, more than one third of the designed capacity. radiation processing is mainly used in producing chemical-industrial products (as heat-shrinkable products and radiation cross-linked wire and cable) in China. Some enterprises with annual output value over a hundred million RMB have emerged. Radiation processing is also used in preservation and disinfection of food. In 1977, six kinds of hygienic standards for irradiated food were authorized. Radiation sterilization of disposable medical products, radiation desulphurization and denitration are also being developed in China

Lunar and Martian environmental interactions with nuclear power system radiators

International Nuclear Information System (INIS)

Perez-Davis, M.E.; Gaier, J.R.; Katzan, C.M.

1994-01-01

In the foreseeable future, NASA space milestones include a permanent manned presence on the Moon and an expedition to the planet Mars. Such steps will require careful consideration of environmental interactions in the selection and design of required power systems. Several environmental constituents may be hazardous to performance integrity. Potential threats common to both the Moon and Mars are low ambient temperatures, wide daily temperature swings, solar flux, and large quantities of dust. The surface of Mars provides the additional challenges of dust storms, winds, and a carbon dioxide atmosphere. In this review, the anticipated environmental interactions with surface power system radiators are described, as well as the impacts of these interactions on radiator durability, which have been identified at NASA Lewis Research Center

Possible radiation injury at Koeberg Nuclear Power Station

International Nuclear Information System (INIS)

Van Rensburg, L.C.J.; De Villiers, B.; Van Zyl, C.J.

1986-01-01

Any injured patient from Koeberg Nuclear Power Station will be treated in the conventional manner as an acute surgical emergency; this has priority over decontamination. The ideal situation is decontamination at Koeberg before ambulance transferral to the Tygerberg Radiation Casualty Facility, but if this is not possible or complete, decontamination can be accomplished by a trained team in the unit. Teamwork is the essence at the place of injury, during transfer, in the decontamination area, in the operating theatre and during the postoperative phase. No surgical management is appropriate or complete without the very necessary guidance and advice from a physicist and the Advisory Group for Radiation Casualties

Lessons learned from Fukushima Daiichi nuclear power plant accident: efficient education items of radiation safety for general public

International Nuclear Information System (INIS)

Ohno, K.; Endo, K.

2015-01-01

The Fukushima Daiichi nuclear power plant (FNP-1) accident, while as tragic as the tsunami, was a man-made disaster created by the ignorance of the effects of radiation and radioactive materials. Therefore, it is important that all specialists in radiation protection in medicine sympathize with the anxiety of the general public regarding the harmful effects of radiation and advise people accordingly. All questions and answers were collected related to inquiries from the general public that were posted to reliable web sites, including those of the government and radiation-related organizations, from March 2011 to November 2012. The questions were summarized and classified by similarity of content. (1) The total number of questions is 372. The content was broadly classified into three categories: inquiries for radiation-related knowledge and about health effects and foods. The questions asked to obtain radiation-related knowledge were the most common, accounting for 38 %. Thirty-six percentage of the questions were related to health effects, and 26 % involved foods, whereas 18 % of the questions were related to children and pregnancy. (2) The change over time was investigated in 290 questions for which the time of inquiry was known. Directly after the earthquake, the questions were primarily from people seeking radiation-related knowledge. Later, questions related to health effects increased. The anxiety experienced by residents following the nuclear accident was caused primarily by insufficient knowledge related to radiation, concerns about health effects and uncertainties about food and water safety. The development of educational materials focusing on such content will be important for risk communication with the general public in countries with nuclear power plants. Physicians and medical physicist should possess the ability to respond to questions such as these and should continue with medical examinations and treatments in a safe and appropriate manner

When the test of mediation is more powerful than the test of the total effect.

Science.gov (United States)

O'Rourke, Holly P; MacKinnon, David P

2015-06-01

Although previous research has studied power in mediation models, the extent to which the inclusion of a mediator will increase power has not been investigated. To address this deficit, in a first study we compared the analytical power values of the mediated effect and the total effect in a single-mediator model, to identify the situations in which the inclusion of one mediator increased statistical power. The results from this first study indicated that including a mediator increased statistical power in small samples with large coefficients and in large samples with small coefficients, and when coefficients were nonzero and equal across models. Next, we identified conditions under which power was greater for the test of the total mediated effect than for the test of the total effect in the parallel two-mediator model. These results indicated that including two mediators increased power in small samples with large coefficients and in large samples with small coefficients, the same pattern of results that had been found in the first study. Finally, we assessed the analytical power for a sequential (three-path) two-mediator model and compared the power to detect the three-path mediated effect to the power to detect both the test of the total effect and the test of the mediated effect for the single-mediator model. The results indicated that the three-path mediated effect had more power than the mediated effect from the single-mediator model and the test of the total effect. Practical implications of these results for researchers are then discussed.

Impact of radiation technique, radiation fraction dose, and total cisplatin dose on hearing. Retrospective analysis of 29 medulloblastoma patients

International Nuclear Information System (INIS)

Scobioala, Sergiu; Kittel, Christopher; Ebrahimi, Fatemeh; Wolters, Heidi; Eich, Hans Theodor; Parfitt, Ross; Matulat, Peter; Am Zehnhoff-Dinnesen, Antoinette

2017-01-01

To analyze the incidence and degree of sensorineural hearing loss (SNHL) resulting from different radiation techniques, fractionation dose, mean cochlear radiation dose (D mean ), and total cisplatin dose. In all, 29 children with medulloblastoma (58 ears) with subclinical pretreatment hearing thresholds participated. Radiotherapy (RT) and cisplatin had been applied sequentially according to the HIT MED Guidance. Audiological outcomes up to the latest follow-up (median 2.6 years) were compared. Bilateral high-frequency SNHL was observed in 26 patients (90%). No significant differences were found in mean hearing threshold between left and right ears at any frequency. A significantly better audiological outcome (p < 0.05) was found after tomotherapy at the 6 kHz bone-conduction threshold (BCT) and left-sided 8 kHz air-conduction threshold (ACT) than after a combined radiotherapy technique (CT). Fraction dose was not found to have any impact on the incidence, degree, and time-to-onset of SNHL. Patients treated with CT had a greater risk of SNHL at high frequencies than tomotherapy patients even though D mean was similar. Increase in severity of SNHL was seen when the total cisplatin dose reached above 210 mg/m 2 , with the highest abnormal level found 8-12 months after RT regardless of radiation technique or fraction dose. The cochlear radiation dose should be kept as low as possible in patients who receive simultaneous cisplatin-based chemotherapy. The risk of clinically relevant HL was shown when D mean exceeds 45 Gy independent of radiation technique or radiation regime. Cisplatin ototoxicity was shown to have a dose-dependent effect on bilateral SNHL, which was more pronounced in higher frequencies. (orig.) [de

Duties and responsibilities of the Nuclear Power Inspectorate and the National Radiation Protection Institute in connection with nuclear power plants

International Nuclear Information System (INIS)

Eckered, T.

1977-01-01

The two Swedish bodies competent for the control of nuclear energy are the Swedish Nuclear Power Inspectorate (SKI) and the National Swedish Institute on Radiation Protection (SSI). The duties of both bodies in respect of inspection stem from the provisions of the Atomic Energy Act and the Radiation Protection Act. The procedure to be followed for construction and operation of nuclear power plants is described from the viewpoint of the responsibilities entrusted to SKI and SSI. (NEA) [fr

Robust, Radiation Tolerant Command and Data Handling and Power System Electronics for SmallSats

Science.gov (United States)

Nguyen, Hanson Cao; Fraction, James

2018-01-01

In today's budgetary environment, there is significant interest within the National Aeronautics and Space Administration (NASA) to enable small robotic science missions that can be executed faster and cheaper than previous larger missions. To help achieve this, focus has shifted from using exclusively radiation-tolerant or radiation-hardened parts to using more commercial-off-the-shelf (COTS) components for NASA small satellite missions that can last at least one year in orbit. However, there are some portions of a spacecraft's avionics, such as the Command and Data Handling (C&DH) subsystem and the Power System Electronics (PSE) that need to have a higher level of reliability that goes beyond what is attainable with currently available COTS parts. While there are a number of COTS components that can withstand a total ionizing dose (TID) of tens or hundreds of kilorads, there is still a great deal of concern about tolerance to and mitigation of single-event effects (SEE).

Electron and Positron Stopping Powers of Materials

Science.gov (United States)

SRD 7 NIST Electron and Positron Stopping Powers of Materials (PC database for purchase)   The EPSTAR database provides rapid calculations of stopping powers (collisional, radiative, and total), CSDA ranges, radiation yields and density effect corrections for incident electrons or positrons with kinetic energies from 1 keV to 10 GeV, and for any chemically defined target material.

Possible standoff detection of ionizing radiation using high-power THz electromagnetic waves

Science.gov (United States)

Nusinovich, Gregory S.; Sprangle, Phillip; Romero-Talamas, Carlos A.; Rodgers, John; Pu, Ruifeng; Kashyn, Dmytro G.; Antonsen, Thomas M., Jr.; Granatstein, Victor L.

2012-06-01

Recently, a new method of remote detection of concealed radioactive materials was proposed. This method is based on focusing high-power short wavelength electromagnetic radiation in a small volume where the wave electric field exceeds the breakdown threshold. In the presence of free electrons caused by ionizing radiation, in this volume an avalanche discharge can then be initiated. When the wavelength is short enough, the probability of having even one free electron in this small volume in the absence of additional sources of ionization is low. Hence, a high breakdown rate will indicate that in the vicinity of this volume there are some materials causing ionization of air. To prove this concept a 0.67 THz gyrotron delivering 200-300 kW power in 10 microsecond pulses is under development. This method of standoff detection of concealed sources of ionizing radiation requires a wide range of studies, viz., evaluation of possible range, THz power and pulse duration, production of free electrons in air by gamma rays penetrating through container walls, statistical delay time in initiation of the breakdown in the case of low electron density, temporal evolution of plasma structure in the breakdown and scattering of THz radiation from small plasma objects. Most of these issues are discussed in the paper.

Protection of radiation induced DNA and membrane damages by total triterpenes isolated from Ganoderma lucidum (Fr.) P. Karst.

Science.gov (United States)

Smina, T P; Maurya, D K; Devasagayam, T P A; Janardhanan, K K

2015-05-25

The total triterpenes isolated from the fruiting bodies of Ganoderma lucidum was examined for its potential to prevent γ-radiation induced membrane damage in rat liver mitochondria and microsomes. The effects of total triterpenes on γ-radiation-induced DNA strand breaks in pBR 322 plasmid DNA in vitro and human peripheral blood lymphocytes ex vivo were evaluated. The protective effect of total triterpenes against γ-radiation-induced micronuclei formations in mice bone marrow cells in vivo were also evaluated. The results indicated the significant effectiveness of Ganoderma triterpenes in protecting the DNA and membrane damages consequent to the hazardous effects of radiation. The findings suggest the potential use of Ganoderma triterpenes in radio therapy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Low-Power Large-Area Radiation Detector for Space Science Measurements

Data.gov (United States)

National Aeronautics and Space Administration — The objective of this task is to develop a low-power, large-area detectors from SiC, taking advantage of very low thermal noise characteristics and high radiation...

Calorimeter with capacitance transducer for measurement of SHF radiation power

International Nuclear Information System (INIS)

Kiselev, V.A.; Linnik, A.F.; Onishchenko, I.N.; Uskov, V.V.

2005-01-01

A calorimeter of simple design for measuring total energy of microwave radiation is described. It operates in the energy range of 0.5 J to 6 kJ; water is used as the absorbing material. A capacitive probe is applied to measure changes in the water volume. The energy absorption factor of electromagnetic radiation in the range of 3-60 GHz is at least 0.9. The calorimeter is insensitive to radiation field nonuniformity over the absorber volume. The calorimeter is intended for measuring the radiation energy of beam plasma generators and generators with dielectric structure. Its design makes it possible to simultaneously measure the radiation energy and monitor the beam current [ru

ITS Version 3.0: Powerful, user-friendly software for radiation modelling

International Nuclear Information System (INIS)

Kensek, R.P.; Halbleib, J.A.; Valdez, G.D.

1993-01-01

ITS (the Integrated Tiger Series) is a powerful, but user-friendly, software package permitting state-of-the-art modelling of electron and/or photon radiation effects. The programs provide Monte Carlo solution of linear time-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields. The ITS system combines operational simplicity and physical accuracy in order to provide experimentalist and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems

Study of national registration systems for health records of radiation workers. National radiation dose registration system

International Nuclear Information System (INIS)

Nakagawa, Haruo; Kanda, Keiji

1999-01-01

A national radiation dose registration system is proposed in this paper. In Japan, only one radiation dose registration system is partly effective. It is applied for workers in nuclear power plants which are under control of regulatory laws for nuclear reactors. The total system was proposed previously by the Committee for Compensation Claims of Nuclear Accidents. The reason for the delay in establishing a registration system for all radiation workers is supposedly a lack of effort to adjust differences among items in radiation protection laws and the promotion of public acceptance to atomic power. Items about dose recordings, record keeping and dose-record reporting in all of the radiation regulatory laws are compared to each other, and items were extracted for revision. (author)

Calculating the Responses of Self-Powered Radiation Detectors.

Science.gov (United States)

Thornton, D. A.

Available from UMI in association with The British Library. The aim of this research is to review and develop the theoretical understanding of the responses of Self -Powered Radiation Detectors (SPDs) in Pressurized Water Reactors (PWRs). Two very different models are considered. A simple analytic model of the responses of SPDs to neutrons and gamma radiation is presented. It is a development of the work of several previous authors and has been incorporated into a computer program (called GENSPD), the predictions of which have been compared with experimental and theoretical results reported in the literature. Generally, the comparisons show reasonable consistency; where there is poor agreement explanations have been sought and presented. Two major limitations of analytic models have been identified; neglect of current generation in insulators and over-simplified electron transport treatments. Both of these are developed in the current work. A second model based on the Explicit Representation of Radiation Sources and Transport (ERRST) is presented and evaluated for several SPDs in a PWR at beginning of life. The model incorporates simulation of the production and subsequent transport of neutrons, gamma rays and electrons, both internal and external to the detector. Neutron fluxes and fuel power ratings have been evaluated with core physics calculations. Neutron interaction rates in assembly and detector materials have been evaluated in lattice calculations employing deterministic transport and diffusion methods. The transport of the reactor gamma radiation has been calculated with Monte Carlo, adjusted diffusion and point-kernel methods. The electron flux associated with the reactor gamma field as well as the internal charge deposition effects of the transport of photons and electrons have been calculated with coupled Monte Carlo calculations of photon and electron transport. The predicted response of a SPD is evaluated as the sum of contributions from individual

Low-Cost Radiator for Fission Power Thermal Control

Science.gov (United States)

Maxwell, Taylor; Tarau, Calin; Anderson, William; Hartenstine, John; Stern, Theodore; Walmsley, Nicholas; Briggs, Maxwell

2014-01-01

NASA Glenn Research Center (GRC) is developing fission power system technology for future Lunar surface power applications. The systems are envisioned in the 10 to 100kW(sub e) range and have an anticipated design life of 8 to 15 years with no maintenance. NASA GRC is currently setting up a 55 kW(sub e) non-nuclear system ground test in thermal-vacuum to validate technologies required to transfer reactor heat, convert the heat into electricity, reject waste heat, process the electrical output, and demonstrate overall system performance. Reducing the radiator mass, size, and cost is essential to the success of the program. To meet these goals, Advanced Cooling Technologies, Inc. (ACT) and Vanguard Space Technologies, Inc. (VST) are developing a single facesheet radiator with heat pipes directly bonded to the facesheet. The facesheet material is a graphite fiber reinforced composite (GFRC) and the heat pipes are titanium/water. By directly bonding a single facesheet to the heat pipes, several heavy and expensive components can be eliminated from the traditional radiator design such as, POC(TradeMark) foam saddles, aluminum honeycomb, and a second facesheet. A two-heat pipe radiator prototype, based on the single facesheet direct-bond concept, was fabricated and tested to verify the ability of the direct-bond joint to withstand coefficient of thermal expansion (CTE) induced stresses during thermal cycling. The thermal gradients along the bonds were measured before and after thermal cycle tests to determine if the performance degraded. Overall, the results indicated that the initial uniformity of the adhesive was poor along one of the heat pipes. However, both direct bond joints showed no measureable amount of degradation after being thermally cycled at both moderate and aggressive conditions.

XXX. Days of Radiation Protection. Conference Proceedings of the 30-th Days of Radiation Protection

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-11-15

The publication has been set up as a proceedings of the conference dealing with health protection during work with ionizing radiation for different activities which involve the handling of ionizing radiation sources. The main conference topics are focused on current problems in radiation protection and radioecology. In this proceedings totally 107 papers are published. The Conference consists of following sections: Effects of ionizing radiation; Regulation of radiation protection; Dosimetry and Metrology of ionizing radiation; Radiation protection in nuclear Power plants; Medical exposure and radiation protection in diagnostic radiology, nuclear medicine and radiation oncology; Natural radioactivity issues in radiation protection; Education, societal aspects and public involvement in radiation protection, trends and perspectives.

XXX. Days of Radiation Protection. Conference Proceedings of the 30-th Days of Radiation Protection

International Nuclear Information System (INIS)

2008-11-01

The publication has been set up as a proceedings of the conference dealing with health protection during work with ionizing radiation for different activities which involve the handling of ionizing radiation sources. The main conference topics are focused on current problems in radiation protection and radioecology. In this proceedings totally 107 papers are published. The Conference consists of following sections: Effects of ionizing radiation; Regulation of radiation protection; Dosimetry and Metrology of ionizing radiation; Radiation protection in nuclear Power plants; Medical exposure and radiation protection in diagnostic radiology, nuclear medicine and radiation oncology; Natural radioactivity issues in radiation protection; Education, societal aspects and public involvement in radiation protection, trends and perspectives

Conversion from HST ACS and STIS auroral counts into brightness, precipitated power and radiated power for H2 giant planets

Science.gov (United States)

Gustin, J.; Bonfond, B.; Grodent, D.; Gerard, J. C.

2012-09-01

The STIS and ACS instruments onboard HST are widely used to study the giant planet's aurora. Several assumptions have to be made to convert the instrumental counts into meaningful physical values (type and bandwidth of the filters, definition of the physical units, etc…), but these may significantly differ from one author to another, which makes it difficult to compare the auroral characteristics published in different studies. We present a method to convert the counts obtained in representative ACS and STIS imaging modes / filters used by the auroral scientific community to brightness, precipitated power and radiated power in the ultraviolet (700- 1800 Å). Since hydrocarbon absorption may considerably affect the observed auroral emission, the conversion factors are determined for several attenuation levels. Several properties of the auroral emission have been determined: the fraction of the H2 emission shortward and longward of the HLy-a line is 50.3 % and 49.7 % respectively, the contribution of HLy-a to the total unabsorbed auroral signal has been set to 9.1 % and an input of 1 mW m-2 produces 10 kR of H2 in the Lyman and Werner bands. A first application sets the order of magnitude of Saturn's auroral characteristics in the total UV bandwidth to a brightness of 10 kR and an emitted power of ~2.8 GW. A second application uses published brighnesses of Europa's footprint to determine the current density associated with the Europa auroral spot: 0.21 and 0.045 μA m-2 assuming no hydrocarbon absorption and a color ratio of 2, respectively.

Near-term Forecasting of Solar Total and Direct Irradiance for Solar Energy Applications

Science.gov (United States)

Long, C. N.; Riihimaki, L. D.; Berg, L. K.

2012-12-01

Integration of solar renewable energy into the power grid, like wind energy, is hindered by the variable nature of the solar resource. One challenge of the integration problem for shorter time periods is the phenomenon of "ramping events" where the electrical output of the solar power system increases or decreases significantly and rapidly over periods of minutes or less. Advance warning, of even just a few minutes, allows power system operators to compensate for the ramping. However, the ability for short-term prediction on such local "point" scales is beyond the abilities of typical model-based weather forecasting. Use of surface-based solar radiation measurements has been recognized as a likely solution for providing input for near-term (5 to 30 minute) forecasts of solar energy availability and variability. However, it must be noted that while fixed-orientation photovoltaic panel systems use the total (global) downwelling solar radiation, tracking photovoltaic and solar concentrator systems use only the direct normal component of the solar radiation. Thus even accurate near-term forecasts of total solar radiation will under many circumstances include inherent inaccuracies with respect to tracking systems due to lack of information of the direct component of the solar radiation. We will present examples and statistical analyses of solar radiation partitioning showing the differences in the behavior of the total/direct radiation with respect to the near-term forecast issue. We will present an overview of the possibility of using a network of unique new commercially available total/diffuse radiometers in conjunction with a near-real-time adaptation of the Shortwave Radiative Flux Analysis methodology (Long and Ackerman, 2000; Long et al., 2006). The results are used, in conjunction with persistence and tendency forecast techniques, to provide more accurate near-term forecasts of cloudiness, and both total and direct normal solar irradiance availability and

Radiation monitoring for the HTTR rise-to-power test (1) and (2)'

Energy Technology Data Exchange (ETDEWEB)

Nakazawa, Takashi; Yoshino, Toshiaki; Yasu, Katsuji; Ashikagaya, Yoshinobu; Kikuchi, Toshiki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

2001-02-01

The High Temperature Engineering Test Reactor (HTTR) is the first high temperature gas-cooled research reactor in Japan. This reactor is a helium-gas-cooled and graphite-moderated reactor with a thermal output of 30 MW. The rated operation temperature of the outlet coolant is 850degC. (During high temperature test operation, this reaches 950degC). The first criticality of the HTTR was attained in November 1998. The single loaded, parallel loaded operation with a thermal output of 9 MW (called the HTTR Rise-to-Power Test (1)) was completed between September 16, 1999 and July 8, 2000. The single loaded, parallel loaded continuous operation with a thermal output of 20 MW (called the HTTR Rise-to-Power Test (2)) has also been carried out, but it was shutdown at the halfway stage by a single from the reactor, when the thermal output was 16.5 MW and the reactor outlet coolant temperature was 500degC. This report describes the radiation monitoring carried out during the HTTR Rise-to-Power Tests (1) and (2)'. The data measured by the various radiation monitors is also reported. These data will be used for the estimation of radiation levels (such as the radiation dose equivalent rate, the radioactive concentration in effluents, etc.) for the next HTTR Rise-to-Power Test, and for periodic inspections. (author)

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

Radiation monitoring complete change by an unprecedented nuclear power plant accident

International Nuclear Information System (INIS)

Omura, Tomomi

2011-01-01

Hydrogen explosion at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company that was triggered by the tsunami generated from the Great East Japan Earthquake led to a series of disasters up to meltdown and melt-through. A large amount of discharge of radioactive substances to the environment due to the disasters marked a sea change in the situation of radiation monitoring in Japan to date. The Japanese Government took the following actions. (1) Establishment of government-led monitoring system through the setup of the Monitoring Coordination Council, (2) Decision on 'Comprehensive Monitoring Program' that implements unified comprehensive radiation monitoring and publishes the results, and (3) Law establishment for radiation monitoring by stipulating immediate implementation systems and implementation points as well as budgetary backup for this purpose. This paper describes the plans to monitor the environment, public facilities, aquatic environment, agricultural land, food, etc., as well as the future challenges. (O.A.)

Acute Radiation Syndrome Severity Score System in Mouse Total-Body Irradiation Model.

Science.gov (United States)

Ossetrova, Natalia I; Ney, Patrick H; Condliffe, Donald P; Krasnopolsky, Katya; Hieber, Kevin P

2016-08-01

Radiation accidents or terrorist attacks can result in serious consequences for the civilian population and for military personnel responding to such emergencies. The early medical management situation requires quantitative indications for early initiation of cytokine therapy in individuals exposed to life-threatening radiation doses and effective triage tools for first responders in mass-casualty radiological incidents. Previously established animal (Mus musculus, Macaca mulatta) total-body irradiation (γ-exposure) models have evaluated a panel of radiation-responsive proteins that, together with peripheral blood cell counts, create a multiparametic dose-predictive algorithm with a threshold for detection of ~1 Gy from 1 to 7 d after exposure as well as demonstrate the acute radiation syndrome severity score systems created similar to the Medical Treatment Protocols for Radiation Accident Victims developed by Fliedner and colleagues. The authors present a further demonstration of the acute radiation sickness severity score system in a mouse (CD2F1, males) TBI model (1-14 Gy, Co γ-rays at 0.6 Gy min) based on multiple biodosimetric endpoints. This includes the acute radiation sickness severity Observational Grading System, survival rate, weight changes, temperature, peripheral blood cell counts and radiation-responsive protein expression profile: Flt-3 ligand, interleukin 6, granulocyte-colony stimulating factor, thrombopoietin, erythropoietin, and serum amyloid A. Results show that use of the multiple-parameter severity score system facilitates identification of animals requiring enhanced monitoring after irradiation and that proteomics are a complementary approach to conventional biodosimetry for early assessment of radiation exposure, enhancing accuracy and discrimination index for acute radiation sickness response categories and early prediction of outcome.

Power plant project success through total productive generation

Energy Technology Data Exchange (ETDEWEB)

Kaivola, R.; Tamminen, L.

1996-11-01

The Total Productive Generation concept (TPG) defines the lines of action adopted by IVO Generation Services Ltd (IGS) for the operation and maintenance of power plants. The TPG concept is based on procedures tested in practice. The main idea of TPG is continuous development of quality, which is a joint effort of the entire staff. Its objective is to benefit IGS`s own staff and, in particular, the company`s customers. (orig.)

Title Investigation of the influence of various factors on the power of heat exchange by radiation

Directory of Open Access Journals (Sweden)

Korolyov Alexander V.

2017-04-01

Full Text Available The issue of lack of knowledge of radiation heat transfer process has been repeatedly raised in various studies. Despite the fact that works on study of heat transfer by radiation covers a wide range of different industries, it should be noted the lack of materials on study of heat exchange processes by radiation in a core of a nuclear reactor. In this work, the fuel assemblies of the VVER-1000 reactor were used as the bodies under study. Aim: The aim of the research is to investigate the heat exchange process between heat transfer assemblies and to study of the effect of changing the distance between the fuel assemblies on their power taking into account the inter-radiating of assemblies. Materials and Methods: A general description of the process of heat transfer by radiation. A calculation study of the effect of geometric parameters on heat transfer in the close lattice of the reactor core is performed. The influence of heat transfer by radiation on the temperature change of the fuel assemblies surface of the VVER-1000 reactor at change in the cassette gap is studied. The change in the power of the fuel assemblies relative to the initial power with a change in the cassette gap was studied. Experimental measurements of the temperature at different distances from the radiation source were made with an obstacle in the path of radiation propagation in the form of glass and water of different levels. The heat radiation and convective heat transfer are calculated based on the obtained experimental data. The calculation of thermal radiation power and convective heat transfer based on the obtained experimental data is performed. Results: The calculation results show that in models that determine the temperature of the fuel assemblies in the core of the VVER-1000 reactor, the radiation heat transfer must be taken into account. In this case, the amount of transferred energy is the greater, the smaller the distance between objects. This is observed

Radiation protection aspects of the repair work at Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Bujtas, T.; Nenyei, A.

2006-01-01

On the Unit 2 at Paks Nuclear Power Plant accident occurred on 10th April 2003. Thirty fuel assemblies damaged in the cleaning tank installed in the Pit No. 1. Due to the accident casing of the fuel elements and uranium-dioxide pellets inside them damaged. The scratched fuel assemblies and nuclear fuel fragments should be removed and safely deposited. In order to restore the operational condition of the Pit No. 1 a lot of complicated activities with radiation hazard should be implemented. These tasks bring up both technical difficulties and serious radiation protection problems, and it is essential to resolve them in order to reduce radiation exposure of the working personnel and to minimize the amount of off-site radioactive releases.There was a serious incident (An INES level 3 event) at Paks Nuclear Power plant in april 10, 2003. (TRA)

Training in radiation protection for personnels in nuclear power plants

International Nuclear Information System (INIS)

Constancis, J.; Gauthier, A.

1980-01-01

For more than 10 years, in order to meet the wishes of their members, the A.P.A.V.E. associations have organised training courses in personnel radiation protection, as a consequence of their activities in the inspection of ionizing radiation sources in industrial or medical environments. Because of their experience, the A.P.A.V.E. associations were asked to provide for the training of the film personnel likely to work in nuclear power stations, in the field of occupational radiation protection. For the last 3 years, nearly 5,000 people have attended these training sessions. The present report describes the approach, draws the first conclusions and state some considerations on this subject [fr

[Radiometers performance attenuation and data correction in long-term observation of total radiation and photosynthetically active radiation in typical forest ecosystems in China].

Science.gov (United States)

Zhu, Zhi-Lin; Sun, Xiao-Min; Yu, Gui-Rui; Wen, Xue-Fa; Zhang, Yi-Ping; Han, Shi-Jie; Yan, Jun-Hua; Wang, Hui-Min

2011-11-01

Based on the total radiation and photosynthetically active radiation (PAR) observations with net radiometer (CNR1) and quantum sensor (Li-190SB) in 4 ChinaFLUX forest sites (Changbaishan, Qianyanzhou, Dinghushan, and Xishuangbanna) in 2003-2008, this paper analyzed the uncertainties and the radiometers performance changes in long-term and continuous field observation. The results showed that the 98% accuracy of the total radiation measured with CNR1 (Q(cNR1)) could satisfy the technical criterion for the sites except Xishuangbanna where the Q(CNR1) was averagely about 7% lower than Q(CM11), the radiation measured with high accuracy pyranometer CM11. For most sites, though the temperature had definite effects on the performance of CNR1, the effects were still within the allowable range of the accuracy of the instrument. Besides temperature, the seasonal fog often occurred in tropical rain forests in Xishuangbanna also had effects on the performance of CNR1. Based on the long-term variations of PAR, especially its ratio to total radiation in the 4 sites, it was found that quantum sensor (Li-190SB) had obvious performance attenuation, with the mean annual attenuation rate being about 4%. To correct the observation error caused by Li-190SB, an attempt was made to give a post-correction of the PAR observations, which could basically eliminate the quantum sensor's performance attenuation due to long-term field measurement.

Earth as a radio source: terrestrial kilometric radiation. Progress report

International Nuclear Information System (INIS)

Gurnett, D.A.

1974-02-01

Radio wave experiments on the IMP-6 and 8 satellites have shown that the earth emits very intense electromagnetic radiation in the frequency range from about 50 kHz to 500 kHz. A peak intensity the total power emitted in this frequency range is about 1 billion watts. The earth is, therefore, a very intense planetary radio source, with a total power output comparable to the decametric radio emission from Jupiter. This radio emission from the earth is referred to as terrestrial kilometric radiation. Terrestrial kilometric radiation appears to originate from low altitudes (less than 3.0 Re) in the auroral region. Possible mechanisms which can explain the generation and propagation of the terrestrial kilometric radiation are discussed. (U.S.)

Resistive vs. total power depositions by Alfven modes in pre-heated low aspect ratio tokamaks

International Nuclear Information System (INIS)

Cuperman, S.; Bruma, C.; Komoshvili, K.

2004-01-01

The power deposition of fast waves launched by a LFS located antenna in a pre-heated, strongly non-uniform low aspect ratio tokamak (START) is investigated. The rigorous computational results indicate a total power deposition by far larger than that predicted for Alfven continuum eigenmodes in cylindrical plasmas. For toroidal wave numbers |N| > 1, the resistive and total power depositions are almost equal. (author)

Time- and dose-dependent effects of total-body ionizing radiation on muscle stem cells

Science.gov (United States)

Masuda, Shinya; Hisamatsu, Tsubasa; Seko, Daiki; Urata, Yoshishige; Goto, Shinji; Li, Tao-Sheng; Ono, Yusuke

2015-01-01

Exposure to high levels of genotoxic stress, such as high-dose ionizing radiation, increases both cancer and noncancer risks. However, it remains debatable whether low-dose ionizing radiation reduces cellular function, or rather induces hormetic health benefits. Here, we investigated the effects of total-body γ-ray radiation on muscle stem cells, called satellite cells. Adult C57BL/6 mice were exposed to γ-radiation at low- to high-dose rates (low, 2 or 10 mGy/day; moderate, 50 mGy/day; high, 250 mGy/day) for 30 days. No hormetic responses in proliferation, differentiation, or self-renewal of satellite cells were observed in low-dose radiation-exposed mice at the acute phase. However, at the chronic phase, population expansion of satellite cell-derived progeny was slightly decreased in mice exposed to low-dose radiation. Taken together, low-dose ionizing irradiation may suppress satellite cell function, rather than induce hormetic health benefits, in skeletal muscle in adult mice. PMID:25869487

INFLUENCE OF THE ORTHOGONALLY POLARIZED BACK REFLECTIONS ON THE POWER AND RADIATION SPECTRUM OF SUPERLUMINESCENT DIODES

Directory of Open Access Journals (Sweden)

A. B. Mukhtubayev

2015-01-01

Full Text Available We have investigated the back reflections influence on the spectrum for optical radiation source of superluminescent diode type and have provided optimal operating conditions of the radiation source. The feature of the research method is the usage of a fiber polarization controller and an optical mirror coated on the end of an optical fiber. The studies were conducted with two sources of optical radiation: ThorLabs superluminescent diode series S5FC1005SXL and LED module ELED-1550-1-E-9-SM1-FA-CW. It was revealed that at the value of back reflections equal to -13 dB relative to the output power source, a negative impact on power and spectral characteristics of the source with an optical power of 2.3 µW is beginning to appear. It was also confirmed that at the increase of the radiation power by increasing the source pumping current, back reflection influence is exhibiting at a lower level of back reflections. The results obtained need to be considered when designing fiber optic sensors in order to eliminate the effect of back reflections on the sources of optical radiation having been studied in this paper.

Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

Science.gov (United States)

Davis, Bette; Gaul, W. C.

2007-01-01

This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.

Pre operational background radiation monitoring around Kudankulam Nuclear Power Project site - a decade long experience

International Nuclear Information System (INIS)

Vijayakumar, B.; George, Thomas; Sundara Rajan, P.; Selvi, B.S.; Balamurugan, M.; Pandit, G.G.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

Pre-operational environmental background radiation monitoring around nuclear power plants is very important to understand baseline values existing in the site and also to identify any hot spots of naturally occurring high background radiation areas and their sources. These baseline measurements will act as a benchmark for future comparison after the reactors go into operation. The radiation measurements are continued during the operational phase of the plant and the results are compared to see whether there is any impact of the operation of the plant on the environment. A comprehensive background radiation monitoring plan has been in vogue at site from 2004 to meet this objective. This paper describes the different monitoring strategies adopted around Kudankulam Nuclear Power Project site and throws light on the pre operational background radiation levels in the environment

National Environmental Radiation Warning And Monitoring Network And Proposed Radiation Monitoring Programme For The 1st Nuclear Power Plant Ninth Thuan

International Nuclear Information System (INIS)

Vuong Thu Bac

2011-01-01

National Environmental Radiation Warning and Monitoring Network has been gradually setting up based on some of legislative documents which have been issued in recent years. Studies and surveys to build an environmental radiation monitoring program for nuclear power plant (NPP) have also been implemented. This paper aims to introduce National Environmental Radiation Warning and Monitoring Network in Vietnam which has been approved by the government, the draft program for environmental radiation monitoring Ninh Thuan NPP and some initial results of research about environmental radiation in the planning area for building first NPP in Vietnam. (author)

Total-dose radiation effects data for semiconductor devices. 1985 supplement. Volume 2, part A

International Nuclear Information System (INIS)

Martin, K.E.; Gauthier, M.K.; Coss, J.R.; Dantas, A.R.V.; Price, W.E.

1986-05-01

Steady-state, total-dose radiation test data, are provided in graphic format for use by electronic designers and other personnel using semiconductor devices in a radiation environment. The data were generated by JPL for various NASA space programs. This volume provides data on integrated circuits. The data are presented in graphic, tabular, and/or narrative format, depending on the complexity of the integrated circuit. Most tests were done using the JPL or Boeing electron accelerator (Dynamitron) which provides a steady-state 2.5 MeV electron beam. However, some radiation exposures were made with a cobalt-60 gamma ray source, the results of which should be regarded as only an approximate measure of the radiation damage that would be incurred by an equivalent electron dose

Chondrosarcoma arising within a radiation-induced osteochondroma several years following childhood total body irradiation: Case report

Energy Technology Data Exchange (ETDEWEB)

Nagata, Shuji [Kurume University Hospital, Department of Radiology, Fukuoka (Japan); Shen, Robert K. [Mayo Clinic, Department of Surgery, Rochester, MN (United States); Laack, Nadia N. [Mayo Clinic, Department of Radiation Oncology, Rochester, MN (United States); Inwards, Carrie Y. [Mayo Clinic, Department of Pathology, Rochester, MN (United States); Wenger, Doris E.; Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

2013-08-15

Malignant degeneration arising in radiation-induced osteochondromas is extremely rare. We report a case of a 34-year-old man with a chondrosarcoma arising from an osteochondroma of the left posterior eighth rib that developed following total body irradiation received as part of the conditioning regimen prior to bone marrow transplantation at age 8. To our knowledge, this is only the fourth reported case of a chondrosarcoma arising within a radiation-induced osteochondroma and the first case occurring following childhood total body irradiation. (orig.)

Chondrosarcoma arising within a radiation-induced osteochondroma several years following childhood total body irradiation: Case report

International Nuclear Information System (INIS)

Nagata, Shuji; Shen, Robert K.; Laack, Nadia N.; Inwards, Carrie Y.; Wenger, Doris E.; Amrami, Kimberly K.

2013-01-01

Malignant degeneration arising in radiation-induced osteochondromas is extremely rare. We report a case of a 34-year-old man with a chondrosarcoma arising from an osteochondroma of the left posterior eighth rib that developed following total body irradiation received as part of the conditioning regimen prior to bone marrow transplantation at age 8. To our knowledge, this is only the fourth reported case of a chondrosarcoma arising within a radiation-induced osteochondroma and the first case occurring following childhood total body irradiation. (orig.)

Lessons learned from Fukushima Daiichi nuclear power plant accident: efficient education items of radiation safety for general public.

Science.gov (United States)

Ohno, K; Endo, K

2015-07-01

The Fukushima Daiichi nuclear power plant (FNP-1) accident, while as tragic as the tsunami, was a man-made disaster created by the ignorance of the effects of radiation and radioactive materials. Therefore, it is important that all specialists in radiation protection in medicine sympathize with the anxiety of the general public regarding the harmful effects of radiation and advise people accordingly. All questions and answers were collected related to inquiries from the general public that were posted to reliable websites, including those of the government and radiation-related organizations, from March 2011 to November 2012. The questions were summarized and classified by similarity of content. (1) The total number of questions is 372. The content was broadly classified into three categories: inquiries for radiation-related knowledge and about health effects and foods. The questions asked to obtain radiation-related knowledge were the most common, accounting for 38 %. Thirty-six percentage of the questions were related to health effects, and 26 % involved foods, whereas 18 % of the questions were related to children and pregnancy. (2) The change over time was investigated in 290 questions for which the time of inquiry was known. Directly after the earthquake, the questions were primarily from people seeking radiation-related knowledge. Later, questions related to health effects increased. The anxiety experienced by residents following the nuclear accident was caused primarily by insufficient knowledge related to radiation, concerns about health effects and uncertainties about food and water safety. The development of educational materials focusing on such content will be important for risk communication with the general public in countries with nuclear power plants. Physicians and medical physicist should possess the ability to respond to questions such as these and should continue with medical examinations and treatments in a safe and appropriate manner. © The

The Japan Power Demonstration Reactor dismantling project. Radiation control

International Nuclear Information System (INIS)

Tomii, Hiroyuki; Seiki, Yoshihiro

1996-01-01

In the Japan Power Demonstration Reactor (JPDR) dismantling project, radiation control was performed properly with routine and special monitoring to keep the occupational safety and to collect data necessary for future dismantling of nuclear facilities. This report describes a summary of radiation control in the dismantling activities and some results of parametric analysis on dose equivalent evaluation, and introduces the following knowledge on radiological protection effectiveness of the dismantling systems applied in the project. a) Use of remote dismantling systems was effective in reducing equivalent workplace exposure. b) Utilization of existing facilities as radiation shield or radioactivity containment was effective in reducing workplace exposure, and also in increasing work efficiency. c) Use of underwater cutting systems was useful to minimize air contamination, and to reduce the dose equivalent rate in the working area. d) In the planning of dismantling, it is necessary to optimize the radiation protection by analyzing dismantling work procedures and evaluating radiological features of the dismantling systems applied, including additional work which the systems require brought from such activities. (author)

Environmental radioactivity and radiation exposure

International Nuclear Information System (INIS)

1980-01-01

In 1977 population exposure in the Federal Republic of Germany has not changed as compared to the previous years. The main share of the total exposure, nearly two thirds, is attributed to natural radioactive substances and cosmic radiation. The largest part (around 85%) of the artificial radiation exposure is caused by X-ray diagnostics. In comparison to this, radiation exposure from application of ionizing radiation in medical therapy, use of radioactive material in research and technology, or from nuclear facilities is small. As in the years before, population exposure caused by nuclear power plants and other nuclear facilities is distinctly less than 1% of the natural radiation exposure. This is also true for the average radiation exposure within a radius of 3 km around nuclear facilities. On the whole, the report makes clear that the total amount of artificial population exposure will substantially decrease only if one succeeds in reducing the high contribution to the radiation exposure caused by medical measures. (orig.) [de

Radiation safety practice at nuclear power stations and estimation of dose burdens to the USSR general public in the context of the country's nuclear power development plans

International Nuclear Information System (INIS)

Vorob'ev, E.I.; Il'in, L.A.; Turovskij, V.D.; Buldakov, L.A.; Lusev, N.G.; Pavlovskij, O.A.; Parkhomenko, G.M.

1983-01-01

The paper sets forth the main features of the State system of health protection for staff and the general public, and likewise the essentials of environmental protection. The principles of standardizing radiation factors are given for power station personnel and for the general public, together with the main provisions of the health Standards and Rules for radiation protection at present valid in the USSR. Data are quoted on the radiation situation at nuclear power stations and on the size of releases of radioactive aerosols and liquid effluents to the environment. The paper pays particular attention to analyses of the radiation situation in districts where nuclear power stations are situated and also to the type and scope of monitoring of radioactive environmental contamination. An analysis of the coefficients achieved with Soviet pressurized water (WWER), high-power channel-type (RBMK) and fast (BN) reactors currently in large-scale use shows that in terms both of release levels of radioactive substances and of the dose burdens to staff and general public these reactors are comparable with the best foreign nuclear power installations. Values actually measured and values calculated for the basic parameters of the radiation situation in areas of the USSR where nuclear power stations are situated confirm the safety of these facilities as regards the health of the general public and the extremely low levels of their effects on the environment. In conclusion, the paper quotes estimates of the collective effective dose equivalent to the USSR population expected to result from implementation of the country's nuclear power programme up to the year 2000. Radiation safety problems associated with nuclear power production which still require solution are enumerated. (author)

Issues behind Radiation management of workers at Fukushima Nuclear Power Plant of Tokyo Electric Power Company. From the viewpoint of radiation exposure of the ocular lens and the biological effects to the lens

International Nuclear Information System (INIS)

Hayashida, Toshiyuki; Sasaki, Hiroshi; Hatsusaka, Natsuko; Hamada, Nobuyuki; Tatsuzaki, Hideo; Akahane, Keiichi; Yokoyama, Sumi

2017-01-01

In March 2011, the accident occurred at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company. During recovery from critical situations, the radiation dose for some emergency workers exceeded the effective dose limit recommended for an emergency situation. A month after the accident, the International Commission on Radiological Protection issued a statement on tissue reactions recommending significant reduction of the equivalent dose limit to the lens of the eye. Many radiation workers will need to be involved in treatment of water contaminated with radionuclides, fuel debris retrieval, and decommissioning of reactors for a long period of time. Thus, the optimized radiation control in the fields, exposure reduction, prevention of tissue reactions, and reduction of stochastic risks for workers becomes necessary. This paper discusses issues in relation to radiation protection of the ocular lens in such recovery workers, from the viewpoint of radiation exposure of workers, its management, manifestations and mechanisms of the lens effects. (author)

Characterization of the temporary radiation workforce at US nuclear power plants

International Nuclear Information System (INIS)

Cehn, J.I.

1984-01-01

The temporary radiation worker is the subject of this recent study by the National Environmental Studies Project. ''Lenny'', an imaginary worker, is actually a composite of the estimated 22,000 radiation workers employed at various times at the 80 nuclear power plants in the U.S. Lenny reports to a trailer on the plant site to check in and spends the next day and a half in a training class that covers radiation safety, federal regulations and exposure limits and plant procedures. He must take and pass a written exam, then he fills out a medical history, indicating whether or not he has received any industrial radiation exposure. After three days of training and ''processing'' he dons a radiation measuring dosimeter and begins work. A key question to this study is whether the temporary employees are getting assigned the dirty work. It has been alleged that temps are used as ''glowboys'' or ''radiation sponges''. The new study finds no basis for this allegation. Data show that permanent plant staff received nearly the same average annual radiation dose as temporary employees

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

Science.gov (United States)

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

2011-04-26

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

Systems analysis of radiation safety during dismantling of power-plant equipment at a nuclear power station

International Nuclear Information System (INIS)

Bylkin, B.K.; Shpitser, V.Ya.

1993-01-01

A systems analysis of the radiation safety makes possible an ad hoc determination of the elements forming the system, as well as the establishment of the characteristics of their interaction with radiation-effect factors. Here the authors will present part of the hierarchical analysis procedure, consisting in general of four separate procedures. The purpose is to investigate and analyze the mean and stable (on the average) indices of radiation safety, within the framework of alternative mathematical models of dismantling the power-plant equipment of a nuclear power station. The following three of the four procedures are discussed: (1) simulated projection, of the processing of radioactive waste; (2) analysis of the redistribution of radionuclides during the industrial cycle of waste treatment; (3) planning the collective dose load during the dismantling operation. Within the framework of the first of these procedures, the solutions to the problem of simulating a waste-treatment operation of maximum efficiency are analyzed. This analysis is based on the use of a data base for the parameters of the installations, assemblies, and equipment, enabling the integration of these in a simulation of a complex automated facility. The results were visualized in an AUTOCAD-10 medium using a graphical data base containing an explanation of the rooms

The design and qualification of radiation tolerant equipment for the nuclear power industry

International Nuclear Information System (INIS)

Sharp, R.; Pater, L.

1995-01-01

The nuclear power industry has many demands for equipment tolerant to the damaging effects of radiation. The wide variety of applications, including components handling, tooling, monitoring and communications, means that a systematic evaluation of the effects of radiation on materials and components used for equipment in radioactive facilities is often required. This paper describes the various effects of radiation on equipment, and discusses how to manage them when using and designing equipment. (Author)

Atmospheric propagation of high power laser radiation at different weather conditions

OpenAIRE

Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Handke, Jürgen

2016-01-01

Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations between weather condition and laser beam characteristics DLR operates at Lampoldshausen a 130 m long fr...

Exploratory study of the radiation-protection training programs in nuclear power plants

International Nuclear Information System (INIS)

Fields, C.D.

1982-06-01

The objective of the study was to examine current radiation training programs at a sample of utilities operating nuclear reactors and to evaluate employee information on radiation health. The study addressed three elements: (1) employee perceptions and understanding of ionizing radiation; (2) utility trainers-their background, training, and problems; (3) the content, materials, and conduct of training programs; (4) program uniformity and completeness. These areas were examined through visits to utilities, surveys, and employee interviews. The programs reviewed were developed by utility personnel who have backgrounds, for the most part, in health physics but who may have little formal training in adult education. This orientation, coupled with the inherent nature of the subject, has produced training programs that appear to be too technical to achieve the educational job intended. The average nuclear power plant worker does not have the level of sophistication needed to understand some of the information. It became apparent that nuclear power plant workers have concerns that do not necessarily reflect those of the scientific community. Many of these result from misunderstandings about radiation. Unfortunately, the training programs do not always address these unfounded but very real fears

Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

International Nuclear Information System (INIS)

Hill, K.W.; Bell, M.G.; Budny, R.

1999-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≥ 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

International Nuclear Information System (INIS)

Hill, K.W.; Bell, M.G.; Budny, R.

2001-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≤30MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

Practice of radiation dose control for tech-modification items in Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Zhang Yong; Chen Zhongyu; Xu Hongming; Fan Liguang; Jiang Jianqi; Bu Weidong

2006-01-01

In order to improve the safety and reliability of nuclear power plant operation, many tech-modifications related to system or equipment have been completed since operation in Qinshan NPP. this paper introduces radiation dose control for mainly tech-modifications items related to radiation, including radiation protection optimization measures and experience in aspects of item planning, program writing, process control, etc. (authors)

Solar Power System Options for the Radiation and Technology Demonstration Spacecraft

Science.gov (United States)

Kerslake, Thomas W.; Haraburda, Francis M.; Riehl, John P.

2000-01-01

The Radiation and Technology Demonstration (RTD) Mission has the primary objective of demonstrating high-power (10 kilowatts) electric thruster technologies in Earth orbit. This paper discusses the conceptual design of the RTD spacecraft photovoltaic (PV) power system and mission performance analyses. These power system studies assessed multiple options for PV arrays, battery technologies and bus voltage levels. To quantify performance attributes of these power system options, a dedicated Fortran code was developed to predict power system performance and estimate system mass. The low-thrust mission trajectory was analyzed and important Earth orbital environments were modeled. Baseline power system design options are recommended on the basis of performance, mass and risk/complexity. Important findings from parametric studies are discussed and the resulting impacts to the spacecraft design and cost.

POWER BEAMING LEAKAGE RADIATION AS A SETI OBSERVABLE

Energy Technology Data Exchange (ETDEWEB)

Benford, James N. [Microwave Sciences, 1041 Los Arabis Lane, Lafayette, CA 94549 (United States); Benford, Dominic J., E-mail: jimbenford@gmail.com [NASA’s Goddard Space Flight Center, Observational Cosmology Laboratory, Greenbelt, MD 20771 (United States)

2016-07-10

The most observable leakage radiation from an advanced civilization may well be from the use of power beaming to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors, and ultimately starships. We estimate the principal observable parameters of power beaming leakage. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC 8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system. We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful, if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be performed, potentially broadening the parameter space of the observable features that we have discussed here.

The computer code system for reactor radiation shielding in design of nuclear power plant

International Nuclear Information System (INIS)

Li Chunhuai; Fu Shouxin; Liu Guilian

1995-01-01

The computer code system used in reactor radiation shielding design of nuclear power plant includes the source term codes, discrete ordinate transport codes, Monte Carlo and Albedo Monte Carlo codes, kernel integration codes, optimization code, temperature field code, skyshine code, coupling calculation codes and some processing codes for data libraries. This computer code system has more satisfactory variety of codes and complete sets of data library. It is widely used in reactor radiation shielding design and safety analysis of nuclear power plant and other nuclear facilities

33. Days of Radiation Protection. Presentations

International Nuclear Information System (INIS)

2011-11-01

The publication has been set up as presentations of the conference dealing with health protection during work with ionizing radiation for different activities which involve the handling of ionizing radiation sources. The main conference topics are focused on the current problems in radiation protection and radioecology. On the web-page totally 103 presentations or posters are published. The Conference consists of the following sections: (I) Effects of ionizing radiation (radiology, health effects, risk factors); (II) General aspects of radiation protection (recommendations and legislative in radiation protection); (III): Dosimetry and metrology of ionizing radiation (metrology, instrumentation, use of computational methods); (IV) Radiation protection in nuclear power industry (working environment in the nuclear industry, the impact on the environment, nuclear power shutdown management); (V) Emergency management (emergencies, accidents, waste); (VI) Radiation load and protection in diagnostics, nuclear medicine and radiation oncology (burden on patients, staff, size of population exposure from medical sources of ionizing radiation, security, and quality control, optimization); (VII) Natural sources of radiation in workplaces and the environment (radon and other radionuclides, the risk estimation, optimization); (VIII) Education (new trends in education of radiation experts, medical physicists and stake-holders).

High-intensity power-resolved radiation imaging of an operational nuclear reactor.

Science.gov (United States)

Beaumont, Jonathan S; Mellor, Matthew P; Villa, Mario; Joyce, Malcolm J

2015-10-09

Knowledge of the neutron distribution in a nuclear reactor is necessary to ensure the safe and efficient burnup of reactor fuel. Currently these measurements are performed by in-core systems in what are extremely hostile environments and in most reactor accident scenarios it is likely that these systems would be damaged. Here we present a compact and portable radiation imaging system with the ability to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has been deployed to image radiation fields emitted during the operation of a TRIGA test reactor allowing a spatial visualization of the internal reactor conditions to be obtained. The imaged flux in each case is found to scale linearly with reactor power indicating that this method may be used for power-resolved reactor monitoring and for the assay of ongoing nuclear criticalities in damaged nuclear reactors.

Research and development of peripheral technology for photovoltaic power systems. Meteorological analysis for suitable design of photovoltaic power generation systems; Shuhen gijutsu no kenkyu kaihatsu. Saiteki sekkei no tame no kisho data no chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

This paper reports the study results on the standard weather data necessary for simulation of PV power generation systems in fiscal 1994. In the study on the selection criterion of the standard weather data from the viewpoint of PV power generation systems, three typical years are used; a year with average solar radiation, and two years with extremely less and more solar radiation for safe simulation. The standard weather data are arranged for output calculation of PV power generation systems by selecting the most typical year based on long-term observation data. The data to be arranged are as follows; total, direct and scattered solar radiations incident upon a horizontal surface, solar radiation upon a slope surface, sunshine duration, air temperature, wind direction, wind velocity, amount of precipitation, and snow depth. For arrangement of the nationwide standard weather data, estimation of total solar radiation is necessary based on sunshine duration data observed by all weather bureaus. In this study, the estimation model was developed of the total solar radiation integrated with time from rotary pyrheliometer data. 5 figs.

Radiation protection training for personnel at light-water-cooled nuclear power plants

International Nuclear Information System (INIS)

Anon.

1981-01-01

Section 19.12 Instructions to Workers, of 10 CFR Part 19, Notices, Instructions, and Reports to Workers; Inspections, requires that individuals be given instruction in radiation protection that is commensurate with the potential radiation protection problems they may encounter in restricted areas as defined in para. 19.3(e) of 10 CFR Part 19. Para. 20.1(c) of 10 CFR Part 20, Standards for Protection Against Radiation, states that occupational radiation exposure should be kept as low as is reasonably achievable (ALARA). Appropriate training is an essential aspect of an ALARA program. This guide describes a radiation protection training program consistent with the ALARA objective and acceptable to the NRC staff for meeting the training requirements of 10 CFR Part 19 with respect to individuals that enter restricted areas at nuclear power plants

Total yield of channeling radiation from relativistic electrons in thin Si and W crystals

International Nuclear Information System (INIS)

Abdrashitov, S.V.; Bogdanov, O.V.; Dabagov, S.B.; Pivovarov, Yu.L.; Tukhfatullin, T.A.

2013-01-01

Orientation dependences of channeling radiation total yield from relativistic 155–855 MeV electrons at both 〈1 0 0〉 axial and (1 0 0) planar channeling in thin silicon and tungsten crystals are studied by means of computer simulations. The model as well as computer code developed allows getting the quantitative results for orientation dependence of channeling radiation that can be used for crystal alignment in channeling experiments and/or for diagnostics of initial angular divergence of electron beam

Radiation monitoring using manned helicopter around the nuclear power station in the fiscal year 2015 (Contract research)

International Nuclear Information System (INIS)

Sanada, Yukihisa; Munakata, Masahiro; Mori, Airi; Ishizaki, Azusa; Shimada, Kazumasa; Hirouchi, Jun; Urabe, Yoshimi; Nakanishi, Chika; Yamada, Tsutomu; Iwai, Takeyuki; Matsunaga, Yuki; Toyoda, Masayuki; Tobita, Shinichiro; Nishizawa, Yukiyasu; Ishida, Mutsushi; Sato, Yoshiharu; Sasaki, Miyuki; Hirayama, Hirokatsu; Takamura, Yoshihide; Nishihara, Katsuya; Imura, Mitsuo; Miyamoto, Kenji; Kudo, Tamotsu; Nakayama, Shinichi

2016-10-01

By the nuclear disaster of Fukushima Daiichi Nuclear Power Station (FDNPS), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPS. After the nuclear disaster, airborne radiation monitoring using manned helicopter was conducted around FDNPS. In addition, background dose rate monitoring was conducted around the Sendai Nuclear Power Station. These results of the aerial radiation monitoring using the manned helicopter in the fiscal 2015 were summarized in the report. In addition, we developed the discrimination technique of the Rn-progenies and the evaluation of radiation attenuation by snow. (author)

Acute care of radioactively contaminated or externally radiated personnel at nuclear power plants

International Nuclear Information System (INIS)

Anon.

1984-01-01

Practical advice is given concerning the treatment of persons injure at nuclear power plant accidents, in particular accidents resulting in contamination or external radiation of man. The folder is primarily directed to persons responsible for the local plannning and supervision of emergency care at the power plant. (L.E.)

An assessment of radiation doses at an educational institution 57.8 km away from the Fukushima Daiichi nuclear power plant 1 month after the nuclear accident.

Science.gov (United States)

Tsuji, Masayoshi; Kanda, Hideyuki; Kakamu, Takeyasu; Kobayashi, Daisuke; Miyake, Masao; Hayakawa, Takehito; Mori, Yayoi; Okochi, Toshiyasu; Hazama, Akihiro; Fukushima, Tetsuhito

2012-03-01

On 11 March 2011, the Great East Japan Earthquake occurred. Due to this earthquake and subsequent tsunami, malfunctions occurred at the Fukushima Daiichi nuclear power plant. Radioactive material even reached the investigated educational institution despite being 57.8 km away from the power station. With the goal of ensuring the safety of our students, we decided to carry out a risk assessment of the premises of this educational institution by measuring radiation doses at certain locations, making it possible to calculate estimated radiation accumulation. Systematic sampling was carried out at measurement points spaced at regular intervals for a total of 24 indoor and outdoor areas, with 137 measurements at heights of 1 cm and 100 cm above the ground surface. Radiation survey meters were used to measure environmental radiation doses. Radiation dose rates and count rates were higher outdoors than indoors, and higher 1 cm above the ground surface than at 100 cm. Radiation doses 1 cm above the ground surface were higher on grass and moss than on asphalt and soil. The estimated radiation exposure for a student spending an average of 11 h on site at this educational institution was 9.80 μSv. Environmental radiation doses at our educational institution 57.8 km away from the Fukushima Daiichi nuclear power plant 1 month after the accident were lower than the national regulation dose for schools (3.8 μSv/h) at most points. Differences in radiation doses depending on outdoor surface properties are important to note for risk reduction.

Radiation practices 1997

International Nuclear Information System (INIS)

Havukainen, R.

1998-05-01

At the end of 1997, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,065 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,839 radiation sources and 302 radionuclide laboratories. The import of radioactive substances amounted to 1.09 x 10 +16 Bq and export to 2.4 x 10 +13 Bq. Short-lived radionuclides produced in Finland amounted to 5.2 x 10 +13 Bq. There were 11,773 workers monitored for radiation exposure at 1,316 work sites. Of these employees, 24% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 6.6 Sv in 1997, with nuclear power plant workers accounting for 62% of this total. The annual dosemeter reading of thirteen medical doctors (radiologists, interventional radiologists and cardiologists) and six nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of the dosemeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 253 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations in which unusually high exposure to radiation was an unavoidable part of the task. Reports were made of four incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Two of these cases occurred in the medical use of radiation, one in the use of radiation sources in industry, and one in the use of solarium appliances. (orig.)

Radiation practices 1997

Energy Technology Data Exchange (ETDEWEB)

Havukainen, R. [ed.

1998-05-01

At the end of 1997, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,065 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,839 radiation sources and 302 radionuclide laboratories. The import of radioactive substances amounted to 1.09 x 10{sup +16} Bq and export to 2.4 x 10{sup +13} Bq. Short-lived radionuclides produced in Finland amounted to 5.2 x 10{sup +13} Bq. There were 11,773 workers monitored for radiation exposure at 1,316 work sites. Of these employees, 24% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 6.6 Sv in 1997, with nuclear power plant workers accounting for 62% of this total. The annual dosemeter reading of thirteen medical doctors (radiologists, interventional radiologists and cardiologists) and six nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of the dosemeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 253 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations in which unusually high exposure to radiation was an unavoidable part of the task. Reports were made of four incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Two of these cases occurred in the medical use of radiation, one in the use of radiation sources in industry, and one in the use of solarium appliances. (orig.)

Radiation power profiles and density limit with a divertor in the W7-AS stellarator

International Nuclear Information System (INIS)

Giannone, L.; Burhenn, R.; McCormick, K.; Brakel, R.; Feng, Y.; Grigull, P.; Igitkhanov, Y.

2002-01-01

The addition of a divertor into the W7-AS stellarator has allowed access to a high density regime where the radiation profiles reach a steady state. In earlier limiter discharges, the plasma suffered a radiative collapse at high densities. In contrast to limiter experiments, where the impurity confinement time measured by Al laser blow-off increased with increasing line integrated density, in divertor discharges, above a density threshold, the impurity confinement time decreased with increasing line integrated density. The observation that the divertor plasma radiates mainly at the plasma edge rather than the plasma centre is a further indication that changes to the impurity transport coefficients at these high densities are the basis for the achievement of steady state discharges in the divertor configuration of W7-AS. The maximum line integrated density reached with a divertor is compared to that reached with a limiter. The previously derived scaling law for the density limit with a limiter shows that the achieved densities do not exceed those predicted when the higher deposited power is taken into account. In a divertor the radiated power is located at the plasma edge and increasing the density, cooling the plasma edge and radiating sufficient power to cause plasma detachment determines the density limit. (author)

Research on prediction of agricultural machinery total power based on grey model optimized by genetic algorithm

Science.gov (United States)

Xie, Yan; Li, Mu; Zhou, Jin; Zheng, Chang-zheng

2009-07-01

Agricultural machinery total power is an important index to reflex and evaluate the level of agricultural mechanization. It is the power source of agricultural production, and is the main factors to enhance the comprehensive agricultural production capacity expand production scale and increase the income of the farmers. Its demand is affected by natural, economic, technological and social and other "grey" factors. Therefore, grey system theory can be used to analyze the development of agricultural machinery total power. A method based on genetic algorithm optimizing grey modeling process is introduced in this paper. This method makes full use of the advantages of the grey prediction model and characteristics of genetic algorithm to find global optimization. So the prediction model is more accurate. According to data from a province, the GM (1, 1) model for predicting agricultural machinery total power was given based on the grey system theories and genetic algorithm. The result indicates that the model can be used as agricultural machinery total power an effective tool for prediction.

Radiation resistance of cable insulation and jacket materials for nuclear power plants

International Nuclear Information System (INIS)

Morita, Minoru; Kon, Shuji; Nishikawa, Ichiro

1978-01-01

The cables for use in nuclear power plants are required to satisfy the specific environmental resistance and excellent flame resistance as stipulated in IEEE Std. 383. The materials to be used to cables intended for this specific purpose of use must therefore be strictly tested so as to evaluate their flame resistance in addition to compliance with various environmental requirements, such as heat resistance, water-vapor resistance, and radiation resistance. This paper describes general information on radiation resistance and deterioration of various high-molecular materials, suggests the direction of efforts to be made to improve their properties including flame resistance of various rubber and plastic materials for cables to be used in nuclear power plants, and indicates the performance characteristics of such materials. (author)

Simulations of hybrid system varying solar radiation and microturbine response time

Directory of Open Access Journals (Sweden)

Yolanda Fernández Ribaya

2015-07-01

Full Text Available Hybrid power systems, such as combinations of renewable power sources with intermittent power production and non-renewable power sources, theoretically increase the reliability and thus integration of renewable sources in the electrical system. However, a recent increase in the number of hybrid installations has sparked interest in the effects of their connection to the grid, especially in remote areas. This paper analyses a photovoltaic-gas microturbine hybrid system dimensioned to be installed in La Paz (Mexico.The research presented in this paper studies and quantifies the effects on the total electric power produced, varying both the solar radiation and the gas microturbine response time. The gas microturbine and the photovoltaic panels are modelled using Matlab/Simulink software, obtaining a platform where different tests to simulate real conditions have been executed. They consist of diverse ramps of irradiance that replicate solar radiation variations, and different microturbine response times reproduced by the time constants of a first order transfer function that models the microturbine dynamic response. The results obtained show that when radiation varies quickly it does not produce significant differences in the power guarantee or the microturbine gas consumption, to any microturbine response time. However, these two parameters are highly variable with smooth radiance variations. The maximum total power variation decreases greatly as the radiation variation gets lower. In addition, by decreasing the microturbine response time, it is possible to appreciably increase the power guarantee although the maximum power variation and gas consumption increase. Only in cases of low radiation variation is there no appreciable difference in the maximum power variation obtained by the different turbine response times.

Simulations of hybrid system varying solar radiation and microturbine response time

Energy Technology Data Exchange (ETDEWEB)

Fernández Ribaya, Yolanda, E-mail: fernandezryolanda@uniovi.es; Álvarez, Eduardo; Paredes Sánchez, José Pablo; Xiberta Bernat, Jorge [Department of Energy E.I.M.E.M., University of Oviedo. 13 Independencia Street 2" n" d floor, 36004, Oviedo (Spain)

2015-07-15

Hybrid power systems, such as combinations of renewable power sources with intermittent power production and non-renewable power sources, theoretically increase the reliability and thus integration of renewable sources in the electrical system. However, a recent increase in the number of hybrid installations has sparked interest in the effects of their connection to the grid, especially in remote areas. This paper analyses a photovoltaic-gas microturbine hybrid system dimensioned to be installed in La Paz (Mexico).The research presented in this paper studies and quantifies the effects on the total electric power produced, varying both the solar radiation and the gas microturbine response time. The gas microturbine and the photovoltaic panels are modelled using Matlab/Simulink software, obtaining a platform where different tests to simulate real conditions have been executed. They consist of diverse ramps of irradiance that replicate solar radiation variations, and different microturbine response times reproduced by the time constants of a first order transfer function that models the microturbine dynamic response. The results obtained show that when radiation varies quickly it does not produce significant differences in the power guarantee or the microturbine gas consumption, to any microturbine response time. However, these two parameters are highly variable with smooth radiance variations. The maximum total power variation decreases greatly as the radiation variation gets lower. In addition, by decreasing the microturbine response time, it is possible to appreciably increase the power guarantee although the maximum power variation and gas consumption increase. Only in cases of low radiation variation is there no appreciable difference in the maximum power variation obtained by the different turbine response times.

Medical aspects of power generation, present and future.

Science.gov (United States)

Linnemann, R E

1979-01-01

It can be seen that the radiation emissions of nuclear power plants are small indeed, compared to natural background radiation and other man-made sources of radiation. For example, the poulation is exposed to 100 times more radiation from television sets than from nuclear power reactors. The assumed risks to the people in this country from nuclear power reactors are also small compared to the normal risks which are tolerated in this society. The complete elimination of all hazards is a most difficult if not impossible task. If we need and desire a certain level of electrical energy, if we must choose between alternative sourves of the energy, then it is apparent that the total impact on our health from nuclear power generation of electricity, under normal operations and in consideration of catastrophic accident probabilities, is significantly less than that of continuing or increasing use of fossil fuels to generate electricity.

Reduction of radiation exposure in Japanese BWR Nuclear Power Plants

International Nuclear Information System (INIS)

Morikawa, Yoshitake

1995-01-01

The reduction of occupational exposure to radiation during the annual inspection and maintenance outages of Japanese boiling water reactors (BWR) is one of the most important objectives for stable and reliable operation. It was shown that this radiation exposure is caused by radionuclides, such as Co-60, Co-58 and Mn-54 which are produced from the metal elements Co, Ni, and Fe present in the corrosion products of structural materials that had been irradiated by neutrons. Therefore, to reduce radiation sources and exposures in Japanese BWRs, attempts have been reinforced to remove corrosion products and activated corrosion products from the primary coolant system. This paper describes the progress of the application of these measures to Japanese BWRs. Most Japanese BWR-4 and BWR-5 type nuclear power plants started their commercial operations during the 1970s. With the elapse of time during operations, a problem came to the forefront, namely that occupational radiation exposure during plant outages gradually increased, which obstructed the smooth running of inspections and maintenance work. To overcome this problem, extensive studies to derive effective countermeasures for radiation exposure reduction were undertaken, based on the evaluation of the plants operation data

Reduction of radiation exposure in Japanese BWR Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Morikawa, Yoshitake [ISOGO Nuclear Engineering Center, Yokohama (Japan)

1995-03-01

The reduction of occupational exposure to radiation during the annual inspection and maintenance outages of Japanese boiling water reactors (BWR) is one of the most important objectives for stable and reliable operation. It was shown that this radiation exposure is caused by radionuclides, such as Co-60, Co-58 and Mn-54 which are produced from the metal elements Co, Ni, and Fe present in the corrosion products of structural materials that had been irradiated by neutrons. Therefore, to reduce radiation sources and exposures in Japanese BWRs, attempts have been reinforced to remove corrosion products and activated corrosion products from the primary coolant system. This paper describes the progress of the application of these measures to Japanese BWRs. Most Japanese BWR-4 and BWR-5 type nuclear power plants started their commercial operations during the 1970s. With the elapse of time during operations, a problem came to the forefront, namely that occupational radiation exposure during plant outages gradually increased, which obstructed the smooth running of inspections and maintenance work. To overcome this problem, extensive studies to derive effective countermeasures for radiation exposure reduction were undertaken, based on the evaluation of the plants operation data.

Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators

Science.gov (United States)

Bernardi, Michael P.; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

2015-01-01

The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses. PMID:26112658

Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

International Nuclear Information System (INIS)

Schultz, E.

1985-01-01

Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

Relative radiation hazards of coal based and nuclear power plants

International Nuclear Information System (INIS)

Mishra, U.C.

1983-04-01

Coal, like most materials found in nature, contains trace quantities of naturally occurring radionuclides. However, low concentrations may become important if large quantities of coal are burnt in thermal power plants. Therefore a study was performed to determine the radioactivity in coal, in fly-ash and slag and assess the importance of radioactive emissions from thermal power plants. The results were compared to the radiological impact of nuclear power stations. Based on these data, theoretical estimates for the population living within 80km from power stations indicate that the collective dose commitments of coal-fired plants are one order of magnitude higher than those for BWR-type nuclear plants. Measurements taken in the vicinity of coal-fired plants were comparable to those for nuclear plants, i.e. within the range of variation of natural background radiation in India

Absorption and scattering of laser radiation by the diffusion flame of aviation kerosene

Energy Technology Data Exchange (ETDEWEB)

Gvozdev, S V; Glova, A F; Dubrovskii, V Yu; Durmanov, S T; Krasyukov, A G; Lysikov, A Yu; Smirnov, G V; Solomakhin, V B

2012-04-30

The absorption coefficient of the radiation of a repetitively pulsed Nd : YAG laser with an average output power up to 6 W and of a cw ytterbium optical fibre laser with an output power up to 3 kW was measured in the diffusion flame of aviation kerosene burning on a free surface in the atmospheric air. The absorption coefficient as a function of flame length, radiation power, and radiation intensity, which was varied in the {approx}10{sup 3} - 5 Multiplication-Sign 10{sup 4} W cm{sup -2} range, was obtained for two distances (1 and 2 cm) between the laser beam axis and the surface. The coefficient of radiation absorption by kerosene flame was compared with that in ethanol and kerosene - ethanol mixture flames. The radiation power scattered by a small segment of the kerosene flame irradiated by Nd : YAG laser radiation was measured as a function of longitudinal and azimuthal coordinates. An estimate was made of the total scattered radiation power.

Absorption and scattering of laser radiation by the diffusion flame of aviation kerosene

International Nuclear Information System (INIS)

Gvozdev, S V; Glova, A F; Dubrovskii, V Yu; Durmanov, S T; Krasyukov, A G; Lysikov, A Yu; Smirnov, G V; Solomakhin, V B

2012-01-01

The absorption coefficient of the radiation of a repetitively pulsed Nd : YAG laser with an average output power up to 6 W and of a cw ytterbium optical fibre laser with an output power up to 3 kW was measured in the diffusion flame of aviation kerosene burning on a free surface in the atmospheric air. The absorption coefficient as a function of flame length, radiation power, and radiation intensity, which was varied in the ∼10 3 - 5×10 4 W cm -2 range, was obtained for two distances (1 and 2 cm) between the laser beam axis and the surface. The coefficient of radiation absorption by kerosene flame was compared with that in ethanol and kerosene - ethanol mixture flames. The radiation power scattered by a small segment of the kerosene flame irradiated by Nd : YAG laser radiation was measured as a function of longitudinal and azimuthal coordinates. An estimate was made of the total scattered radiation power.

Absorption and scattering of laser radiation by the diffusion flame of aviation kerosene

Science.gov (United States)

Gvozdev, S. V.; Glova, A. F.; Dubrovskii, V. Yu; Durmanov, S. T.; Krasyukov, A. G.; Lysikov, A. Yu; Smirnov, G. V.; Solomakhin, V. B.

2012-04-01

The absorption coefficient of the radiation of a repetitively pulsed Nd : YAG laser with an average output power up to 6 W and of a cw ytterbium optical fibre laser with an output power up to 3 kW was measured in the diffusion flame of aviation kerosene burning on a free surface in the atmospheric air. The absorption coefficient as a function of flame length, radiation power, and radiation intensity, which was varied in the ~103 — 5×104 W cm-2 range, was obtained for two distances (1 and 2 cm) between the laser beam axis and the surface. The coefficient of radiation absorption by kerosene flame was compared with that in ethanol and kerosene — ethanol mixture flames. The radiation power scattered by a small segment of the kerosene flame irradiated by Nd : YAG laser radiation was measured as a function of longitudinal and azimuthal coordinates. An estimate was made of the total scattered radiation power.

Safety and radiation protection in Indian nuclear power plants

International Nuclear Information System (INIS)

Ghadge, S.G.

2008-01-01

Full text: Nuclear energy, an important option for electricity generation is environment friendly, technologically proven, economically competitive and associated with the advantages of energy security and diversity. At present, India has an installed nuclear power generation capacity of 4120 M We with 6 more reactors are under construction/ commissioning at 4 sites. Nuclear power program, in India, as of now is primarily based on pressurized heavy water technology and these reactors are designed with safety features, such as, independent and diverse shut down systems, emergency core cooling system, double containment; pressure suppression pool etc. The principles of redundancy, diversity, fail-safe and passive systems are used in the design. The fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. In this regard the prime responsibility for safety rests with the organization responsible for facilities and activities that give rise to radiation risks and is achieved by establishing and maintaining the necessary competence, providing adequate training and information, establishing procedures and arrangements to maintain safety under all conditions; verifying appropriate design and the adequate quality of facilities and activities and of their associated equipment; ensuring the safe control of all radioactive material that is used, produced, stored or transported, ensuring the safe control of all radioactive waste that is generated. 'Radiation Protection for Nuclear Facilities', issued by Atomic Energy Regulatory Board (the regulatory authority for NPPs in India) is the basic document for following radiation protection procedures in NPPs. Approved work procedures for all radiation jobs exist. Pre job briefing and post job analysis are carried out. Radiation protection is integrated with plant operation. Radiation levels indicate the performance of several systems. Several measures are adopted in design and

Power spectral density and scaling exponent of high frequency global solar radiation sequences

Science.gov (United States)

Calif, Rudy; Schmitt, François G.; Huang, Yongxiang

2013-04-01

The part of the solar power production from photovlotaïcs systems is constantly increasing in the electric grids. Solar energy converter devices such as photovoltaic cells are very sensitive to instantaneous solar radiation fluctuations. Thus rapid variation of solar radiation due to changes in the local meteorological condition can induce large amplitude fluctuations of the produced electrical power and reduce the overall efficiency of the system. When large amount of photovoltaic electricity is send into a weak or small electricity network such as island network, the electric grid security can be in jeopardy due to these power fluctuations. The integration of this energy in the electrical network remains a major challenge, due to the high variability of solar radiation in time and space. To palliate these difficulties, it is essential to identify the characteristic of these fluctuations in order to anticipate the eventuality of power shortage or power surge. The objective of this study is to present an approach based on Empirical Mode Decomposition (EMD) and Hilbert-Huang Transform (HHT) to highlight the scaling properties of global solar irradiance data G(t). The scale of invariance is detected on this dataset using the Empirical Mode Decomposition in association with arbitrary-order Hilbert spectral analysis, a generalization of (HHT) or Hilbert Spectral Analysis (HSA). The first step is the EMD, consists in decomposing the normalized global solar radiation data G'(t) into several Intrinsic Mode Functions (IMF) Ci(t) without giving an a priori basis. Consequently, the normalized original solar radiation sequence G'(t) can be written as a sum of Ci(t) with a residual rn. From all IMF modes, a joint PDF P(f,A) of locally and instantaneous frequency f and amplitude A, is estimated. To characterize the scaling behavior in amplitude-frequency space, an arbitrary-order Hilbert marginal spectrum is defined to: Iq(f) = 0 P (f,A)A dA (1) with q × 0 In case of scale

Radiation control system

International Nuclear Information System (INIS)

Murao, Mitsuo.

1985-01-01

Purpose: To rapidly and suitably performing planning and designation by radiation-working control systems in the radiation controlled area of nuclear power plant. Method: Various informations regarding radiation exposure are arranged and actual exposure data are statistically stored, to thereby perform forecasting calculation for the radiation exposure upon workings in the plurality of working regions in the radiation controlled area. Based on the forecast values and the registered workers' exposure dose in the past workings are alocated successively such that the total exposure does upon conducting the workings is less than the limited value, to prepare working plans in the areas. Further, procedures for preparing a series of documents regarding the workings in the radiation area are automated to rapidly and properly provide the informations serving to the planning and designation for the radiation workings. As a result, the radiation managers' burnden can be mitigated and an efficient working management system can be provided, in view of the exposure management and personal management. (Kamimura, M.)

Investigation of Improved Methods in Power Transfer Efficiency for Radiating Near-Field Wireless Power Transfer

Directory of Open Access Journals (Sweden)

Hesheng Cheng

2016-01-01

Full Text Available A metamaterial-inspired efficient electrically small antenna is proposed, firstly. And then several improving power transfer efficiency (PTE methods for wireless power transfer (WPT systems composed of the proposed antenna in the radiating near-field region are investigated. Method one is using a proposed antenna as a power retriever. This WPT system consisted of three proposed antennas: a transmitter, a receiver, and a retriever. The system is fed by only one power source. At a fixed distance from receiver to transmitter, the distance between the transmitter and the retriever is turned to maximize power transfer from the transmitter to the receiver. Method two is using two proposed antennas as transmitters and one antenna as receiver. The receiver is placed between the two transmitters. In this system, two power sources are used to feed the two transmitters, respectively. By adjusting the phase difference between the two feeding sources, the maximum PTE can be obtained at the optimal phase difference. Using the same configuration as method two, method three, where the maximum PTE can be increased by regulating the voltage (or power ratio of the two feeding sources, is proposed. In addition, we combine the proposed methods to construct another two schemes, which improve the PTE at different extent than classical WPT system.

Modal analysis and nonlinear characterization of an airborne power ultrasonic transducer with rectangular plate radiator.

Science.gov (United States)

Andrés, R R; Acosta, V M; Lucas, M; Riera, E

2018-01-01

Some industrial processes like particle agglomeration or food dehydration among others can be enhanced by the use of power ultrasonic technologies. These technologies are based on an airborne power ultrasonic transducer (APUT) constituted by a pre-stressed Langevin-type transducer, a mechanical amplifier and an extensive plate radiator. In order to produce the desired effects in industrial processing, the transducer has to vibrate in an extensional mode driving an extensive radiator in the desired flexural mode with high amplitude displacements. Due to the generation of these high amplitude displacements in the radiator surfaces, non-linear effects like frequency shifts, hysteresis or modal interactions, among others, may be produced in the transducer behavior. When any nonlinear effect appears, when applying power, the stability and efficiency of this ultrasonic technology decreases, and the transducer may be damaged depending on the excitation power level and the nature of the nonlinearity. In this paper, an APUT with flat rectangular radiator is presented, as the active part of an innovative system with stepped reflectors. The nonlinear behavior of the APUT has been characterized numerically and experimentally in case of the modal analysis and experimentally in the case of dynamic analysis. According to the results obtained after the experiments, no modal interactions are expected, nor do other nonlinear effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Highly Radiative Plasmas for Local Transport Studies and Power and Particle Handling in Reactor Regimes

International Nuclear Information System (INIS)

Bell, M.G.; Bell, R.E.; Budny, R.; Bush, C.E.; Hill, K.W.

1998-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into the Tokamak Fusion Test Reactor (TFTR) supershots and high-l(subscript) plasmas. At neutral beam injection (NBI) powers P(subscript B) greater than or equal to 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both deuterium (D) and deuterium-tritium (DT) plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in the International Thermonuclear Experimental Reactor (ITER). The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms

Total radiative width (Γγ) as a function of mass number A

International Nuclear Information System (INIS)

Huynh, V.D.; Barros, S. De; Chevillon, P.L.; Julien, J.; Poittevin, G. Le; Morgenstern, J.; Samour, C.

1967-01-01

The total radiative width Γ γ was measured accurately for a large number of nuclei. These values, which are important for reactor calculations, are difficult to determine. The fluctuations in Γ γ from resonance to resonance in the same nucleus are discussed in terms of level parity and the de-excitation scheme. The authors compare the experimental values with those predicted by theory. (author) [fr

A knowledge on environmental radiation monitoring about the influence from Fukushima Dai-ichi Nuclear Power accident

International Nuclear Information System (INIS)

Yoshioka, Mitsuo; Terakawa, Kazuyoshi; Kasai, Toshihiro

2012-01-01

A large amount of radioactive substances were released in the atmosphere and contaminated a large area across Japan due to the accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company triggered by Great East Japan Earthquake and tsunami on May 11th 2011. At Fukui University of Technology, monitoring of air radiation (gamma ray) and radiation in environmental samples in Fukui prefecture and some areas of Fukushima prefecture were conducted in order to study the influence of radiation and radioactivity on the citizens as well as the perception of this study results by the citizens. Also, in order to study the dependency of the radiation influence on the distance from the accident location, radiation monitoring of fallouts (air-borne dust, rainwater, sediment mud, and so on) was conducted. In this article, the knowledge obtained on environmental radiation monitoring was summarized and reported. Especially, slightly modified dose-level evaluation for internal exposure was reported. (S.K.)

Novel circuits for radiation hardened memories

International Nuclear Information System (INIS)

Haraszti, T.P.; Mento, R.P.; Moyer, N.E.; Grant, W.M.

1992-01-01

This paper reports on implementation of large storage semiconductor memories which combine radiation hardness with high packing density, operational speed, and low power dissipation and require both hardened circuit and hardened process technologies. Novel circuits, including orthogonal shuffle type of write-read arrays, error correction by weighted bidirectional codes and associative iterative repair circuits, are proposed for significant improvements of SRAMs' immunity against the effects of total dose and cosmic particle impacts. The implementation of the proposed circuit resulted in fault-tolerant 40-Mbit and 10-Mbit monolithic memories featuring a data rate of 120 MHz and power dissipation of 880 mW. These experimental serial-parallel memories were fabricated with a nonhardened standard CMOS processing technology, yet provided a total dose hardness of 1 Mrad and a projected SEU rate of 1 x 10 - 12 error/bit/day. Using radiation hardened processing improvements by factors of 10 to 100 are predicted in both total dose hardness and SEU rate

Radiation hardening of CMOS-based circuitry in SMART transmitters

International Nuclear Information System (INIS)

Loescher, D.H.

1993-02-01

Process control transmitters that incorporate digital signal processing could be used advantageously in nuclear power plants; however, because such transmitters are too sensitive to radiation, they are not used. The Electric Power Research Institute sponsored work at Sandia National Laboratories under EPRI contract RP2614-58 to determine why SMART transmitters fail when exposed to radiation and to design and demonstrate SMART transmitter circuits that could tolerate radiation. The term ''SMART'' denotes transmitters that contain digital logic. Tests showed that transmitter failure was caused by failure of the complementary metal oxide semiconductors (CMOS)-integrated circuits which are used extensively in commercial transmitters. Radiation-hardened replacements were not available for the radiation-sensitive CMOS circuits. A conceptual design showed that a radiation-tolerant transmitter could be constructed. A prototype for an analog-to-digital converter subsection worked satisfactorily after a total dose of 30 megarads(Si). Encouraging results were obtained from preliminary bench-top tests on a dc-to-dc converter for the power supply subsection

Test and Evaluation of Fiber Optic Sensors for High-Radiation Space Nuclear Power Applications

International Nuclear Information System (INIS)

Klemer, Daniel; Fielder, Robert S.; Stinson-Bagby, Kelly L.

2004-01-01

Fiber optic sensors can be used to measure a number of parameters, including temperature, strain, pressure and flow, for instrumentation and control of space nuclear power systems. In the past, this technology has often been rejected for use in such a high-radiation environment based on early experiments that revealed a number of degradation phenomena, including radiation-induced fiber attenuation, or 'graying', and Fiber Bragg Grating (FBG) fading and wavelength shift. However, this paper reports the results of recent experimental testing that demonstrates readability of fiber optic sensors to extremely high levels of neutron and gamma radiation. Both distributed Fiber Bragg Grating (FBG) sensors and single-point Extrinsic Fabry Perot Interferometer (EFPI) sensors were continuously monitored over a 2-month period, during which they were exposed to combined neutron and gamma radiation in both in-core and ex-core positions within a nuclear reactor. Total exposure reached approximately 2 x 10 19 cm -2 fast neutron (E > 1 MeV) fluence and 8.7 x 10 8 Gy gamma for in-core sensors. FBG sensors were interrogated using a standard Luna Innovations FBG measurement system, which is based on optical frequency-domain reflectometer (OFDR) technology. Approximately 74% of the 19 FBG sensors located at the core centerline in the in-core position exhibited sufficient signal-to-noise ratio (SNR) to remain readable even after receiving the maximum dose. EFPI sensors were spectrally interrogated using a broadband probe source operating in the 830 nm wavelength region. While these single-point sensors failed early in the test, important additional fiber spectral transmission data was collected, which indicates that interrogation of EFPI sensors in alternate wavelength regions may allow significant improvement in sensor longevity for operation in high-radiation environments. This work was funded through a Small Business Innovative Research (SBIR) contract with the Nasa Glenn Research

Estimates of power requirements for a Manned Mars Rover powered by a nuclear reactor

Science.gov (United States)

Morley, Nicholas J.; El-Genk, Mohamed S.; Cataldo, Robert; Bloomfield, Harvey

1991-01-01

This paper assesses the power requirement for a Manned Mars Rover vehicle. Auxiliary power needs are fulfilled using a hybrid solar photovoltaic/regenerative fuel cell system, while the primary power needs are meet using an SP-100 type reactor. The primary electric power needs, which include 30-kW(e) net user power, depend on the reactor thermal power and the efficiency of the power conversion system. Results show that an SP-100 type reactor coupled to a Free Piston Stirling Engine yields the lowest total vehicle mass and lowest specific mass for the power system. The second lowest mass was for a SP-100 reactor coupled to a Closed Brayton Cycle using He/Xe as the working fluid. The specific mass of the nuclear reactor power system, including a man-rated radiation shield, ranged from 150-kg/kW(e) to 190-kg/KW(e) and the total mass of the Rover vehicle varied depend upon the cruising speed.

Measures of radiation protection in the operation of nuclear power plants in the German Democratic Republic

International Nuclear Information System (INIS)

Richter, D.; Schreiter, W.

1975-11-01

A survey is given on the provisions concerning (a) radiation protection at nuclear power plants in the GDR including the instructions applying within the plant, (b) the organization of radiation protection services, and (c) the measures of radiation protection surveillance inside and outside the plant during operation. (author)

Radiation effects on electronic equipment: a designers'/users' guide for the nuclear power industry

International Nuclear Information System (INIS)

Sharp, R.E.; Garlick, D.R.

1994-01-01

The Designers'/Users' Guide to the effects of radiation on electronics is published by the Radiation Testing Service of AEA Technology. The aim of the Guide is to document the available information that we have generated and collected over some ten years whilst operating as a radiation effects and design consultancy to the nuclear power industry. We hope that this will enable workers within the industry better to understand the likely effects of radiation on the system or plant being designed and so minimise the problems that can arise. (Author)

Review of problems and methods for radiation risk assessment in the environment of a nuclear power plant

International Nuclear Information System (INIS)

Grgic, M.

1966-01-01

Radiation impact on the nuclear power plant environment is a very important problem which has to be solved during design and construction. Damage that could be caused by release of radioactive material into the environment should be estimated and the magnitude of nuclear and radiation risk of the power plant should be evaluated. In general the accuracy of estimation is rather poor due to statistical fluctuations of the conditions which influence radioactivity expansion in the environment, especially in the air. Different uncertainties and unresolved problems influence the inaccuracy. Since any real risk should be extremely small compared to potential risk i.e. risk induced by nuclear power plant without any safety measures, even inaccurate estimations are very useful. Method for environmental radiation risk assessment is based on relatively simple models of radiation expansion in the environment and in the air. These models are theoretically solved but they are based on relatively limited number of experimental data. Assessment of the radiation effects on the population health and mortality is an important problem [sl

THz calorimetry : An absolute power meter for TeraHertz radiation and the absorptivity of the Herschel Space Observatory telescope mirror coating

NARCIS (Netherlands)

Klaassen, T.O.; Hovenier, J.N.; Fischer, J.; Jakob, G.; Poglitsch, A.; Sternberg, O.

2004-01-01

A new calorimetric absolute power meter has been developed for THz radiation. This broad band THz power meter measures average power at ambient temperature and pressure, does not use a window, and is insensitive to polarization and time structure of THz radiation. The operation of the power meter is

Multilayer mirrors as power filters in insertion device beamlines

International Nuclear Information System (INIS)

Kortright, J.B.; DiGennaro, R.S.

1988-08-01

The power-filtering capabilities of multilayer band-pass x-ray mirrors relative to total reflection low-pass mirrors is presented. Results are based on calculations assuming proposed wiggler sources on the upcoming generation of low energy (1.5 GeV) and high energy (7.0 GeV) synchrotron radiation sources. Results show that multilayers out-perform total reflection mirrors in terms of reduction in reflected power by roughly an order of magnitude, with relatively small increases in total absorbed power and power density over total reflection mirrors, and with comparable reflected flux values. Various aspects of this potential application of multilayer x-ray optics are discussed. 13 refs., 3 figs., 1 tab

The regulatory evaluation of radiation protection training programmes at Canadian nuclear power plants

International Nuclear Information System (INIS)

Legare, M.; Tennant, D.

1996-01-01

The responsibility for providing the necessary assurance that the use of nuclear energy in Canada does not pose undue risk to health, safety, security and the environment is vested with the Atomic Energy Control Board (AECB). This responsibility has led the Operator Certification Division of the AECB to develop methods to obtain assurance that nuclear power plant operations personnel are well trained and adequately competent to perform their duties. The features of the AECB approach to evaluation of training programmes based on a systematic approach to training is described. An overview of the Canadian nuclear power plants' radiation protection qualification levels is given. The developing evaluation process is contributing to the improvement of licensee radiation protection training programmes. This is making possible the transfer of part of the responsibility for licensed personnel radiation protection qualification assessment to the licensees, thus enabling a reduction in the operator certification division formal qualification activities. (author)

Ultraviolet radiation and air contamination during total hip replacement

International Nuclear Information System (INIS)

Carlsson, A.S.; Nilsson, B.; Walder, M.H.; Osterberg, K.

1986-01-01

Ultraviolet (uv) radiation of the operating room was assessed bacteriologically in an open randomized study of 30 total hip procedures. Volumetric air-sampling demonstrated that the number of colony forming units (cfu m-3) were significantly reduced (P less than 0.001) by uv light, both close to the wound and in the periphery of the operating room. No adverse effects of the uv-irradiation were observed either in the patients or the staff. In operating rooms fitted with a zonal ventilation system and with an air change rate of about 70 h-1, the addition of uv irradiation during surgery may achieve ultra clean air. However, in conventionally ventilated operating rooms uv-irradiation alone is probably not sufficient to do so

Antenna-coupled terahertz radiation from joule-heated single-wall carbon nanotubes

Directory of Open Access Journals (Sweden)

M. Muthee

2011-12-01

Full Text Available In this letter an experimental method is introduced that allows detection of terahertz (THz radiation from arrays of joule-heated Single-Walled Carbon Nanotubes (SWCNTs, by coupling this radiation through integrated antennas and a silicon lens. The radiation forms a diffraction-limited beam with a total maximum radiated power of 450 nW, significantly greater than the power estimated from Nyquist thermal noise (8 nW. The physical radiation process is unknown at this stage, but possible explanations for the high radiated power are discussed briefly. The emission has a typical bandwidth of 1.2 THz and can be tuned to different frequencies by changing the dimensions of the antennas. Arrays of the devices could be integrated in CMOS integrated circuits, and find application in THz systems, such as in near-range medical imaging.

Optimized tokamak power exhaust with double radiative feedback in ASDEX Upgrade

Science.gov (United States)

Kallenbach, A.; Bernert, M.; Eich, T.; Fuchs, J. C.; Giannone, L.; Herrmann, A.; Schweinzer, J.; Treutterer, W.; the ASDEX Upgrade Team

2012-12-01

A double radiative feedback technique has been developed on the ASDEX Upgrade tokamak for optimization of power exhaust with a standard vertical target divertor. The main chamber radiation is measured in real time by a subset of three foil bolometer channels and controlled by argon injection in the outer midplane. The target heat flux is in addition controlled by nitrogen injection in the divertor private flux region using either a thermoelectric sensor or the scaled divertor radiation obtained by a bolometer channel in the outer divertor. No negative interference of the two radiation controllers has been observed so far. The combination of main chamber and divertor radiative cooling extends the operational space of a standard divertor configuration towards high values of P/R. Pheat/R = 14 MW m-1 has been achieved so far with nitrogen seeding alone as well as with combined N + Ar injection, with the time-averaged divertor peak heat flux below 5 MW m-2. Good plasma performance can be maintained under these conditions, namely H98(y,2) = 1 and βN = 3.

Generating high-power short terahertz electromagnetic pulses with a multifoil radiator.

Science.gov (United States)

Vinokurov, Nikolay A; Jeong, Young Uk

2013-02-08

We describe a multifoil cone radiator capable of generating high-field short terahertz pulses using short electron bunches. Round flat conducting foil plates with successively decreasing radii are stacked, forming a truncated cone with the z axis. The gaps between the foil plates are equal and filled with some dielectric (or vacuum). A short relativistic electron bunch propagates along the z axis. At sufficiently high particle energy, the energy losses and multiple scattering do not change the bunch shape significantly. When passing by each gap between the foil plates, the electron bunch emits some energy into the gap. Then, the radiation pulses propagate radially outward. For transverse electromagnetic waves with a longitudinal (along the z axis) electric field and an azimuthal magnetic field, there is no dispersion in these radial lines; therefore, the radiation pulses conserve their shapes (time dependence). At the outer surface of the cone, we have synchronous circular radiators. Their radiation field forms a conical wave. Ultrashort terahertz pulses with gigawatt-level peak power can be generated with this device.

Quantitative comparisons between experimentally measured 2-D carbon radiation and Monte Carlo impurity (MCI) code simulations

International Nuclear Information System (INIS)

Evans, T.E.; Leonard, A.W.; West, W.P.; Finkenthal, D.F.; Fenstermacher, M.E.; Porter, G.D.

1998-08-01

Experimentally measured carbon line emissions and total radiated power distributions from the DIII-D divertor and Scrape-Off Layer (SOL) are compared to those calculated with the Monte Carlo Impurity (MCI) model. A UEDGE background plasma is used in MCI with the Roth and Garcia-Rosales (RG-R) chemical sputtering model and/or one of six physical sputtering models. While results from these simulations do not reproduce all of the features seen in the experimentally measured radiation patterns, the total radiated power calculated in MCI is in relatively good agreement with that measured by the DIII-D bolometric system when the Smith78 physical sputtering model is coupled to RG-R chemical sputtering in an unaltered UEDGE plasma. Alternatively, MCI simulations done with UEDGE background ion temperatures along the divertor target plates adjusted to better match those measured in the experiment resulted in three physical sputtering models which when coupled to the RG-R model gave a total radiated power that was within 10% of measured value

Occupational radiation exposure at commercial nuclear power reactors and other facilities, 1990: Twenty-third annual report

International Nuclear Information System (INIS)

Raddatz, C.T.

1993-01-01

This report summarizes the occupational radiation exposure information that has been reported to the NRC's Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC licensees during the years 1969 through 1990. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10 CFR 20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC licensed facilities were obtained from reports submitted pursuant to 10 CFR 20.408. The 1990 annual reports submitted by about 443 licensees indicated that approximately 214,568 individuals were monitored, 110,204 of whom were monitored by nuclear power facilities. They incurred an average individual dose of 0.19 rem (cSv) and an average measurable dose of about 0.36 (cSv). Termination radiation exposure reports were analyzed to reveal that about 113,361 individuals completed their employment with one or more of the 443 covered licensees during 1990. Some 77,633 of these individuals terminated from power reactor facilities, and about 11,083 of them were considered to be transient workers who received an average dose of 0.67 rem (cSv)

Radiation monitoring data on the power-up test of HTTR. Results up to 20 MW operation

International Nuclear Information System (INIS)

Ashikagaya, Yoshinobu; Nakazawa, Takashi; Yoshino, Toshiaki; Yasu, Katsuji

2002-01-01

The High Temperature Engineering Test Reactor (HTTR) have completed the Power-up test of 9 MW (the single and parallel loaded operation) in the rated operation mode. After that the Power-up test in the rated operation mode and the high-temperature test operation mode with a thermal output of 20 MW (the single and parallel loaded operation) were performed between January 16, 2001 and June 10, 2001. This report describes the radiation monitoring data carried out during the HTTR Power-up test in the rated operation mode and the high-temperature test operation mode with a thermal output of 20 MW. The followings were concluded from these radiation monitoring data. The monitoring of radioactive gaseous effluents and the radiation protection for the works will be easy to do and the exposure dose of the workers will be kept the low level. (author)

Radiation safety and the resurgence of nuclear power in the U.S

International Nuclear Information System (INIS)

Harrall, Tom P. Jr.

2008-01-01

Today, in the United States, 104 reactors in 31 states produce electricity for one in five homes and businesses. They have achieved record levels of performance, and their safety levels are unmatched in the U.S. industry. They are the largest source of emission-free electricity in the U.S. and are vital in maintaining the stability of the country's electrical grid. This outstanding record of performance of the U.S. commercial nuclear fleet has laid a solid basis for the next generation of nuclear plants. There is growing interest in adding new nuclear capacity in the U.S., with public announcements having been made expressing intentions to prepare applications for up to 33 new nuclear units at 22 sites in the U.S. To date, seven applications have been filed with the U.S. Nuclear Regulatory Commission (NRC) for new nuclear units. Duke Energy is one of the largest electric power companies in the United States. We supply and deliver energy to approximately 4 million U.S. customers. We have approximately 36,000 megawatts of electric generating capacity in the Midwest and the Carolinas, and natural gas distribution services in Ohio and Kentucky. In addition, we have more than 4,000 megawatts of electric generation in Latin America. Duke operates three nuclear stations with a total capacity of just under 7,000 megawatts in North Carolina and South Carolina. These three stations -Catawba, Mc Guire and Oconee- have each received approval from the NRC for extended operations beyond their initial 40-year license term. On December 13, 2007, Duke submitted a construction and operating license (COL) application to the NRC for the William States Lee III Nuclear Station to be built in South Carolina. A partnership between the U.S. nuclear industry, the Nuclear Energy Institute (NEI), the Electric Power Research Institute (EPRI) and the Institute for Nuclear Power Operations (INPO) was formed to influence the regulatory structure, pursue technology improvements and innovations

Use of BEIR V and UNSCEAR 1988 in radiation risk assessment: Lifetime total cancer mortality risk estimates at low doses and low dose rates for low-LET radiation

International Nuclear Information System (INIS)

1992-12-01

In November 1986, the Department of Defense (DoD) asked the Committee on Interagency Radiation Research and Policy Coordination (CIRRPC) to develop a coordinated Federal position on risk assessment for low levels of ionizing radiation. Since Federal risk assessment activities are based primarily on the scientific data and analyses in authoritative review documents prepared by groups like the National Academy of Sciences' Committee on the Biological Effects of Ionizing Radiation (BEIR), the National Council on Radiation Protection and Measurements (NCRP) and the United Nations' Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), DoD proposed that the CIRRPC Science Panel undertake the task of providing coordinated interagency positions on the use of information in the reports of such groups. The practice has been for individual Federal agencies to interpret and decide independently how to use the information provided in such reports. As a result of its deliberations, the Subpanel recommends two nominal risk estimates for lifetime total cancer mortality following whole-body exposure to low levels of low-LET ionizing radiation, one for the general population and one for the working-age population (see Section II). The recommended risk estimates reflect the general agreement of information in BEIR V and UNSCEAR 1988 for total cancer mortality. The Subpanel's risk estimates and associated statements are intended to meet the needs of the Federal agencies for: (a) values that are current; (b) values that are relevant to the low-dose and low dose-rate ionizing radiation exposures principally encountered in carrying out Federal responsibilities; (c) a statement of the change in the estimates of lifetime total cancer mortality relative to estimates in previous authoritative review documents; and (d) a practical statement on the scientific uncertainty associated with applying the lifetime total cancer mortality values at very low doses

Radiation protection programme at Krsko nuclear power plant

International Nuclear Information System (INIS)

Breznik, B.

1996-01-01

Krsko NPP, a Westinghouse two-loop PWR of 632 M We power, is in commercial operation since 1982. Reduction of radioactive releases to the environment and the reduction of doses to workers is the basic goal in the plant radiological protection. The radiation protection programme is established to ensure that the radiation exposures to workers and members of the public are minimized according to the As Low As Reasonably Achievable approach and controlled in accordance with international safety standards and Slovenian regulations. The basis for the operational and technical measures has been provided according to the industrial good practice. The effluent control is based on the Standard Radioactive Effluent Technical Specifications, and environmental surveillance is established according to the programme defined by the regulations. The dose constraints and performance indicators are used to assure the effectiveness of the radiation protection programme and provide a convenient follow-up tool. The monitoring programme results of each year show that there is no measurable dose to the public due to radioactive releases. The commitment to the dose burden of any member of a critical group is assessed to be below the dose constraint. Individual and collective doses of the workers are within a range typical for the PWRs of a similar type. (author)

Total Magnetic Field Signatures over Submarine HVDC Power Cables

Science.gov (United States)

Johnson, R. M.; Tchernychev, M.; Johnston, J. M.; Tryggestad, J.

2013-12-01

Mikhail Tchernychev, Geometrics, Inc. Ross Johnson, Geometrics, Inc. Jeff Johnston, Geometrics, Inc. High Voltage Direct Current (HVDC) technology is widely used to transmit electrical power over considerable distances using submarine cables. The most commonly known examples are the HVDC cable between Italy and Greece (160 km), Victoria-Tasmania (300 km), New Jersey - Long Island (82 km) and the Transbay cable (Pittsburg, California - San-Francisco). These cables are inspected periodically and their location and burial depth verified. This inspection applies to live and idle cables; in particular a survey company could be required to locate pieces of a dead cable for subsequent removal from the sea floor. Most HVDC cables produce a constant magnetic field; therefore one of the possible survey tools would be Marine Total Field Magnetometer. We present mathematical expressions of the expected magnetic fields and compare them with fields observed during actual surveys. We also compare these anomalies fields with magnetic fields produced by other long objects, such as submarine pipelines The data processing techniques are discussed. There include the use of Analytic Signal and direct modeling of Total Magnetic Field. The Analytic Signal analysis can be adapted using ground truth where available, but the total field allows better discrimination of the cable parameters, in particular to distinguish between live and idle cable. Use of a Transverse Gradiometer (TVG) allows for easy discrimination between cable and pipe line objects. Considerable magnetic gradient is present in the case of a pipeline whereas there is less gradient for the DC power cable. Thus the TVG is used to validate assumptions made during the data interpretation process. Data obtained during the TVG surveys suggest that the magnetic field of a live HVDC cable is described by an expression for two infinite long wires carrying current in opposite directions.

Prototypes of Self-Powered Radiation Detectors Employing Intrinsic High-Energy Current (HEC) (POSTPRINT)

Science.gov (United States)

2016-01-01

neutron sensi- tivities of a Pt self - powered detector ,” IEEE Trans. Nucl. Sci. 25, 292–295 (1978). 6T. A. Dellin, R. E. Huddleston, and C. J...Gamma-sensitive self - powered detectors and their use for in-core flux -mapping,” IEEE Trans. Nucl. Sci. 28, 752–757 (1981). 9E. A. Burke and J. Wall...AFCEC-CX-TY-TP-2016-0006 PROTOTYPES OF SELF - POWERED RADIATION DETECTORS EMPLOYING INTRINSIC HIGH-ENERGY CURRENT (HEC) (POSTPRINT) Piotr

Study on Pyroelectric Harvesters Integrating Solar Radiation with Wind Power

Directory of Open Access Journals (Sweden)

Chun-Ching Hsiao

2015-07-01

Full Text Available Pyroelectric harvesters use temperature fluctuations to generate electrical outputs. Solar radiation and waste heat are rich energy sources that can be harvested. Pyroelectric energy converters offer a novel and direct energy-conversion technology by transforming time-dependent temperatures directly into electricity. Moreover, the great challenge for pyroelectric energy harvesting lies in finding promising temperature variations or an alternating thermal loading in real situations. Hence, in this article, a novel pyroelectric harvester integrating solar radiation with wind power by the pyroelectric effect is proposed. Solar radiation is a thermal source, and wind is a dynamic potential. A disk generator is used for harvesting wind power. A mechanism is considered to convert the rotary energy of the disk generator to drive a shutter for generating temperature variations in pyroelectric cells using a planetary gear system. The optimal period of the pyroelectric cells is 35 s to harvest the stored energy, about 70 μJ, while the rotary velocity of the disk generator is about 31 RPM and the wind speed is about 1 m/s. In this state, the stored energy acquired from the pyroelectric harvester is about 75% more than that from the disk generator. Although the generated energy of the proposed pyroelectric harvester is less than that of the disk generator, the pyroelectric harvester plays a complementary role when the disk generator is inactive in situations of low wind speed.

Accelerating an Ordered-Subset Low-Dose X-Ray Cone Beam Computed Tomography Image Reconstruction with a Power Factor and Total Variation Minimization.

Science.gov (United States)

Huang, Hsuan-Ming; Hsiao, Ing-Tsung

2016-01-01

In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate.

Impact of a Disposable Sterile Radiation Shield on Operator Radiation Exposure During Percutaneous Coronary Intervention of Chronic Total Occlusions.

Science.gov (United States)

Shorrock, Deborah; Christopoulos, Georgios; Wosik, Jedrek; Kotsia, Anna; Rangan, Bavana; Abdullah, Shuaib; Cipher, Daisha; Banerjee, Subhash; Brilakis, Emmanouil S

2015-07-01

Daily radiation exposure over many years can adversely impact the health of medical professionals. Operator radiation exposure was recorded for 124 percutaneous coronary interventions (PCIs) performed at our institution between August 2011 and May 2013: 69 were chronic total occlusion (CTO)-PCIs and 55 were non-CTO PCIs. A disposable radiation protection sterile drape (Radpad; Worldwide Innovations & Technologies, Inc) was used in all CTO-PCI cases vs none of the non-CTO PCI cases. Operator radiation exposure was compared between CTO and non-CTO PCIs. Mean age was 64.6 ± 6.2 years and 99.2% of the patients were men. Compared with non-CTO PCI, patients undergoing CTO-PCI were more likely to have congestive heart failure, to be current smokers, and to have longer lesions, and less likely to have prior PCI and a saphenous vein graft target lesion. CTO-PCI cases had longer procedural time (median: 123 minutes [IQR, 85-192 minutes] vs 27 minutes [IQR, 20-44 minutes]; P<.001), fluoroscopy time (35 minutes [IQR, 19-54 minutes] vs 8 minutes [IQR, 5-16 minutes]; P<.001), number of stents placed (2.4 ± 1.5 vs 1.7 ± 0.9; P<.001), and patient air kerma radiation exposure (3.92 Gray [IQR, 2.48-5.86 Gray] vs 1.22 Gray [IQR, 0.74-1.90 Gray]; P<.001), as well as dose area product (267 Gray•cm² [IQR, 163-4.25 Gray•cm²] vs 84 Gray•cm² [IQR, 48-138 Gray•cm²]; P<.001). In spite of higher patient radiation exposure, operator radiation exposure was similar between the two groups (20 μSv [IQR, 9.5-31 μSv] vs 15 μSv [IQR, 7-23 μSv]; P=.07). Operator radiation exposure during CTO-PCI can be reduced to levels similar to less complicated cases with the use of a disposable sterile radiation protection shield.

Environmental radiation monitoring during visits of nuclear powered warships to Australian ports: requirements, arrangements and procedures

International Nuclear Information System (INIS)

1988-05-01

The Commonwealth Government has determined conditions to be met when nuclear powered warships visit Australian ports. These conditions include a requirement that appropriate State/Territory and Commonwealth authorities provide a radiation monitoring program to determine whether any radioactivity has been discharged or accidently released from a nuclear powered warship in port; to determine actual or potential levels of any consequent exposure to radiation of members of the public; and to provide this information within a timescale that allows remedial action to be taken. Part 1 of this document sets out the requirements of a radiation monitoring program capable of meeting these objectives. The fundamental arrangements and procedures for implementing the requirements are presented at Part 2 and provide a basis for the development of fully detailed, port specific, radiation monitoring programs

Periodic table as a powerful tool for radiation education

International Nuclear Information System (INIS)

Aratani, Michi; Osanai, Yuko; Uchiumi, Fumiko; Tsushima, Kazuko; Kamayachi, Tei; Kudo, Michiko

2005-01-01

The periodic tables ordinarily start with an element of atomic number 1, hydrogen. Hydrogen atoms, however, are derived from neutrons by way of β decay. Consequently, neutron should be located at a zero position of atomic number, which corresponds to the left side and above helium. A periodic table, especially with the zero position for neutron, is essential from present view of matter and serves as a powerful tool for radiation education. (author)

Radiation and Environmental Protection Programme for the First Upcoming Nuclear Power Plant in Indonesia

International Nuclear Information System (INIS)

Syahrir

2007-01-01

Indonesia plans to operate the first nuclear power plant (NPP) by 2016. A radiation and environmental protection arrangement for NPPs is part of the whole safety system which is embedded in every practice involved radiation exposure to workers and members of public. A radiation and environmental protection programme for the NPP should adhere to international standards and mainstream in order to be acceptable to the public and international communities. International Atomic Energy Agency (IAEA) has recommended a radiation protection standard for NPPs as studied in this paper. Focus is given to the operational aspects of radiation protection program and discharge control to the environment. Some documents related to Safety Analysis Reports were used as working examples on its implementation. The study includes the classification of working areas and access control; local rules and supervision of work; work planning and work permits; protective clothing and protective equipment; facilities, shielding and equipment; application of the principle of optimization of protection; and removal or reduction in intensity of sources of radiation. The radiological protection aspects blend together in the whole NPP practices, each individual has his/her own responsibility in association with the radiation protection program implementation. It also present in the whole steps of NPP preparation up to its decommissioning. Promise on safety improvement and significant dose reduction in the recent development in NPP technology should scrutinized so that the option of proven technology as required in commercial power reactor licensing considers this tendency. (author)

Emesis as a Screening Diagnostic for Low Dose Rate (LDR) Total Body Radiation Exposure.

Science.gov (United States)

Camarata, Andrew S; Switchenko, Jeffrey M; Demidenko, Eugene; Flood, Ann B; Swartz, Harold M; Ali, Arif N

2016-04-01

Current radiation disaster manuals list the time-to-emesis (TE) as the key triage indicator of radiation dose. The data used to support TE recommendations were derived primarily from nearly instantaneous, high dose-rate exposures as part of variable condition accident databases. To date, there has not been a systematic differentiation between triage dose estimates associated with high and low dose rate (LDR) exposures, even though it is likely that after a nuclear detonation or radiologic disaster, many surviving casualties would have received a significant portion of their total exposure from fallout (LDR exposure) rather than from the initial nuclear detonation or criticality event (high dose rate exposure). This commentary discusses the issues surrounding the use of emesis as a screening diagnostic for radiation dose after LDR exposure. As part of this discussion, previously published clinical data on emesis after LDR total body irradiation (TBI) is statistically re-analyzed as an illustration of the complexity of the issue and confounding factors. This previously published data includes 107 patients who underwent TBI up to 10.5 Gy in a single fraction delivered over several hours at 0.02 to 0.04 Gy min. Estimates based on these data for the sensitivity of emesis as a screening diagnostic for the low dose rate radiation exposure range from 57.1% to 76.6%, and the estimates for specificity range from 87.5% to 99.4%. Though the original data contain multiple confounding factors, the evidence regarding sensitivity suggests that emesis appears to be quite poor as a medical screening diagnostic for LDR exposures.

Radiation risk from the nuclear power installation of space vehicle in case of reentry to the atmosphere

International Nuclear Information System (INIS)

Mikheenko, S.G.

1994-01-01

Main directions of space using of nuclear power are considered. Nuclear energy has found many applications in space projects. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear power for propulsion purposes in space flight. History of usage nuclear power systems in space technic is shown. Today there are 54 satellites with NPS in space near the Earth. The main principle of radical solution of the problem of radiation safety is based on the accommodation of space objects with nuclear units in orbits, such that the ballistic lifetime is greater than the time necessary for complete decay of the accumulated radioactivity. Radiation safety on various stages of space nuclear systems exploitation is discussed. If Main System Ensuring Radiation Safety is failed, it must operates Reserved System Ensuring Radiation Safety. Concrete development of a booster system for nuclear unit and a system for the reactor destruction in order to ensure aerodynamic destruction of fuel has been realized in satellite of 'Cosmos' series. The investigations on reserved system ensuring radiation safety in Moscow Physical - Engineering Institute are discussed. The results show that we can in principle ensure the radiation safety in accordance to ICRP recommendations. (author)

Total radiation dosage from X-ray examinations in rheumatoid arthritis and other chronic skeletal diseases

International Nuclear Information System (INIS)

Baldursson, H.; Gustafsson, M.

1977-01-01

Young patients with rheumatoid arthritis and other chronic diseases of the skeleton are increasingly being operated on with replacement of major joints. The great number of associated X-ray examinations performed on these patients has caused some anxiety amongst orthopaedic surgeons. Two patients with juvenile rheumatoid arthritis have been studied. An attempt was made to calculate the total radiation dose to bone marrow and gonads. For lack of recommendations for the maximum permissible radiation dose to patients, the dose calculated has been compared with the maximum permissible dose of radiation workers, and with the dose limit for non-occupational irradiation of individuals. The yearly absorbed dose in these two patients is much lower than the maximum permissible dose of radiation workers and only slightly higher than the dose limit for non-occupational exposure of individuals. (author)

Introduction to symposium 'radiation protection at nuclear facilities'

International Nuclear Information System (INIS)

Stricker, L.

1996-01-01

An introduction to the symposium 'radiation protection of nuclear facilities' on Wednesday, April 17, 1996 in Vienna has been given. The number of operating reactors and the total collective dose per reactor in OECD countries has been discussed. The evolution of the total collective dose associated with the replacement of steam generators at nuclear power reactors from 1979 to 1995 is presented. The background and culture of radiation protection, regulatory aspects, strategic formulation, plan management policy and organization responsibilities are discussed generally. (Suda)

AlGaAs/GaAs photovoltaic converters for high power narrowband radiation

Energy Technology Data Exchange (ETDEWEB)

Khvostikov, Vladimir; Kalyuzhnyy, Nikolay; Mintairov, Sergey; Potapovich, Nataliia; Shvarts, Maxim; Sorokina, Svetlana; Andreev, Viacheslav [Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021 (Russian Federation); Luque, Antonio [Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021, Russia and Instituto de Energia Solar, Universidad Politecnica de Madrid, Madrid (Spain)

2014-09-26

AlGaAs/GaAs-based laser power PV converters intended for operation with high-power (up to 100 W/cm{sup 2}) radiation were fabricated by LPE and MOCVD techniques. Monochromatic (λ = 809 nm) conversion efficiency up to 60% was measured at cells with back surface field and low (x = 0.2) Al concentration 'window'. Modules with a voltage of 4 V and the efficiency of 56% were designed and fabricated.

Fractal characteristics correlation between the solar total radiation and net radiation on the apple tree canopy

International Nuclear Information System (INIS)

Meng Ping; Zhang Jingsong

2005-01-01

The characteristics correlation between solar total radiations(Q) and net radiation(R n) on the apple tree canopy at mainly growth stage in the hilly of Taihang Mountain are analyzed with fractal theory based on regression analysis. The results showed that:1)Q and R n had good liner correlation. The regression function was as the following:R n=0.740 8Q-32.436, which coefficient r is 0.981 1(n=26 279), F cal= 343 665.2 F 0.01 36 277=6.63; 2)The fractal dimension curves of Q and R n both had two no s caling regions, which circumscription time value of the inflexion was 453 and 441 minutes respectively.In the first region, fractal dimensions of Q and R n was 1.112 6, 1.131 9 respectively,and 1.913 6@@@ 1.883 4 in the second region.Those information showed that fractal characteristics of Q and R n is similar. So R n can be calculated with Q on the apple tree canopy

Current scaling of radiated power for 40-mm diameter single wire arrays on Z

Science.gov (United States)

Nash, T. J.; Cuneo, M. E.; Spielman, R. B.; Chandler, G. A.; Leeper, R. J.; Seaman, J. F.; McGurn, J.; Lazier, S.; Torres, J.; Jobe, D.; Gilliland, T.; Nielsen, D.; Hawn, R.; Bailey, J. E.; Lake, P.; Carlson, A. L.; Seamen, H.; Moore, T.; Smelser, R.; Pyle, J.; Wagoner, T. C.; LePell, P. D.; Deeney, C.; Douglas, M. R.; McDaniel, D.; Struve, K.; Mazarakis, M.; Stygar, W. A.

2004-11-01

In order to estimate the radiated power that can be expected from the next-generation Z-pinch driver such as ZR at 28 MA, current-scaling experiments have been conducted on the 20 MA driver Z. We report on the current scaling of single 40 mm diameter tungsten 240 wire arrays with a fixed 110 ns implosion time. The wire diameter is decreased in proportion to the load current. Reducing the charge voltage on the Marx banks reduces the load current. On one shot, firing only three of the four levels of the Z machine further reduced the load current. The radiated energy scaled as the current squared as expected but the radiated power scaled as the current to the 3.52±0.42 power due to increased x-ray pulse width at lower current. As the current is reduced, the rise time of the x-ray pulse increases and at the lowest current value of 10.4 MA, a shoulder appears on the leading edge of the x-ray pulse. In order to determine the nature of the plasma producing the leading edge of the x-ray pulse at low currents further shots were taken with an on-axis aperture to view on-axis precursor plasma. This aperture appeared to perturb the pinch in a favorable manner such that with the aperture in place there was no leading edge to the x-ray pulses at lower currents and the radiated power scaled as the current squared ±0.75. For a full-current shot we will present x-ray images that show precursor plasma emitting on-axis 77 ns before the main x-ray burst.

Radiation exposure of employees in nuclear fuel facilities in fiscal 1982

International Nuclear Information System (INIS)

1984-01-01

The enterprises of nuclear fuel refining, fabrication, reprocessing and usage are obligated by law to keep the radiation exposure dose of the employees below the permissible level. The radiation exposure dose in the respective enterprises in the fiscal year 1982 is summarized in a table as follows: radiation exposure dose distribution, the number of employees, total exposure dose, and average dose. The radiation exposure dose was all well below the permissible level. The enterprises covered were one refining (Power Reactor and Nuclear Fuel Development Corporation), five fabrication (Mitsubishi Nuclear Fuel Co., Ltd., etc.), one reprocessing (Power Reactor and Nuclear Fuel Development Corporation), and ten usage (Power Reactor and Nuclear Fuel Development Corporation, Japan Atomic Energy Research Institute, etc.). (Mori, K.)

Total life cycle cost model for electric power stations

International Nuclear Information System (INIS)

Cardullo, M.W.

1995-01-01

The Total Life Cycle Cost (TLCC) model for electric power stations was developed to provide a technology screening model. The TLCC analysis involves normalizing cost estimates with respect to performance standards and financial assumptions and preparing a profile of all costs over the service life of the power station. These costs when levelized present a value in terms of a utility electricity rate. Comparison of cost and the pricing of the electricity for a utility shows if a valid project exists. Cost components include both internal and external costs. Internal costs are direct costs associated with the purchase, and operation of the power station and include initial capital costs, operating and maintenance costs. External costs result from societal and/or environmental impacts that are external to the marketplace and can include air quality impacts due to emissions, infrastructure costs, and other impacts. The cost stream is summed (current dollars) or discounted (constant dollars) to some base year to yield a overall TLCC of each power station technology on a common basis. While minimizing life cycle cost is an important consideration, it may not always be a preferred method for some utilities who may prefer minimizing capital costs. Such consideration does not always result in technology penetration in a marketplace such as the utility sector. Under various regulatory climates, the utility is likely to heavily weigh initial capital costs while giving limited consideration to other costs such as societal costs. Policy makers considering external costs, such as those resulting from environmental impacts, may reach significantly different conclusions about which technologies are most advantageous to society. The TLCC analysis model for power stations was developed to facilitate consideration of all perspectives

Evaluation of the Total Cost of Ownership of Fuel Cell-Powered Material Handling Equipment

Energy Technology Data Exchange (ETDEWEB)

Ramsden, T.

2013-04-01

This report discusses an analysis of the total cost of ownership of fuel cell-powered and traditional battery-powered material handling equipment (MHE, or more typically 'forklifts'). A number of fuel cell MHE deployments have received funding support from the federal government. Using data from these government co-funded deployments, DOE's National Renewable Energy Laboratory (NREL) has been evaluating the performance of fuel cells in material handling applications. NREL has assessed the total cost of ownership of fuel cell MHE and compared it to the cost of ownership of traditional battery-powered MHE. As part of its cost of ownership assessment, NREL looked at a range of costs associated with MHE operation, including the capital costs of battery and fuel cell systems, the cost of supporting infrastructure, maintenance costs, warehouse space costs, and labor costs. Considering all these costs, NREL found that fuel cell MHE can have a lower overall cost of ownership than comparable battery-powered MHE.

Radiation resistance of thin-film solar cells for space photovoltaic power

Science.gov (United States)

Woodyard, James R.; Landis, Geoffrey A.

1991-01-01

Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

Radiation monitoring handbook for visits by nuclear powered warships to Australian ports

International Nuclear Information System (INIS)

Woods, D.A.

1995-09-01

The purpose of this handbook is to detail the Radiation Monitoring (RMG) roles and procedures, and to provide technical and background information useful to RMG personnel. It has been written on the assumption that all members of the RMG have had appropriate radiation safety (Health Physics) training. Separate standing procedures, for both routine and emergency activities, are required for each port. These are incorporated in Port Safety Plans and specify the routine monitoring requirements for individual berths or anchorages and the procedures to be followed after indication of a reactor accident to a nuclear powered warship. A Visit Operation Order, issued for each Nuclear Powered warships (NPW) visit, presents information specific to that visit. Routine monitoring is performed to confirm normal conditions. The objectives of emergency radiation monitoring are: to provide early detection of a reactor accident of sufficient severity to possibly cause a major release of fission products to the environment; to determine the nature and extent of any fission product release; to provide information to assist in evaluating the accident; to assess the need and extent of required countermeasures; and to determine when the release has terminated and when affected areas have returned to normal

Safety and Radiation Protection at Swedish Nuclear Power Plants 2004

International Nuclear Information System (INIS)

2005-05-01

higher inspector presence than normal and more stringent reporting requirements. In SKI's opinion, Barsebaeck Kraft AB (BKAB), with the measures that have been implemented, is maintaining safety at the Barsebaeck nuclear power plant. In December, Studsvik Nuclear AB decided to close down the two reactors at Studsvik. Therefore, SKI immediately initiated an intensified supervision of the decommissioning process at the reactors. The handling of nuclear waste at nuclear power plants, including the operation of the Repository for Low and Intermediate-level Operational Waste (SFR-1) and the Central Interim Storage Facility for Spent Nuclear Fuel (CLAB) has largely functioned well for the most part. In 2004, the total radiation dose to the personnel at nuclear power plants was 6.4 manSv, which is lower than in 2003. The average value for the past five years is 9 manSv. The shutdown periods were shorter at a few reactors due to the fact that work progress surpassed expectations. Technical problems and unplanned repair work resulted in a somewhat higher dose than expected at a few reactors. No individual received a radiation dose greater than 20 mSv. The fuel defects that occurred in 2004 did not result in any significant impact on radiation protection. The dose to people living in the vicinity of the nuclear power plants in 2004 was below 1 per cent of the permitted dose. The control measurements that SSI conducts on environmental samples around nuclear power plants and on the radioactive releases to water show a good agreement with the licensees' own measurements

The Educational Effects of basic Nuclear Power and Radiation Education on Elementary-, Middle-, and High-School Students in 2012-2013

International Nuclear Information System (INIS)

Kim, Jae Rok; Lee, Seung Koo; Choi, Yoon Seok; Hahm, Young Kyu; Lee, Ji Eun; Han, Eun Ok

2014-01-01

Due to the cognitive anchoring of both powerful and negative images, such as those concerning the Chernobyl accident and the Fukushima nuclear accident, as well as insufficient post-accident management following such events, the general population's perception of risk regarding technology or institutions related to nuclear energy is heavily affected by the occurrence of these nuclear accidents. Because the acceptability of local and general residents serves as a prerequisite to nuclear power institutions and policies, increasing the social acceptability of nuclear power is important in South Korea, where the continuous use of nuclear power is necessary for the security of its nationwide energy supply and economic growth. By focusing education regarding nuclear power generation and radiation use on elementary-, middle-, and high-school students, who will, out of the general population, likely experience some of the greatest ripple effects from this focused education, the relationship between perception, knowledge, and attitude regarding nuclear power generation and radiation were then analyzed. The goals of this analysis were to help form an extensive and national social consensus regarding nuclear power generation and radiation use that is appropriate to South Korea, and improve the understanding and public perceptions of the aforementioned technology of the people of South Korea. In order for radiation technology to power national developments through the next generation, understanding and acceptance of for radiation technology by the general population must come first. In order to effectively provide data about this understanding and acceptance, elementary-, middle-, and high-school students all of whom will constitute the majority of public opinion in the near future were provided basic education regarding radiation use and nuclear power. Their perceptions before and after the intervention, as well as their knowledge and attitude as based on traditional

The Educational Effects of basic Nuclear Power and Radiation Education on Elementary-, Middle-, and High-School Students in 2012-2013

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Rok; Lee, Seung Koo; Choi, Yoon Seok; Hahm, Young Kyu; Lee, Ji Eun; Han, Eun Ok [Department of Education and Research, Korea Academy of Nuclear Safety, Seoul (Korea, Republic of)

2014-10-15

Due to the cognitive anchoring of both powerful and negative images, such as those concerning the Chernobyl accident and the Fukushima nuclear accident, as well as insufficient post-accident management following such events, the general population's perception of risk regarding technology or institutions related to nuclear energy is heavily affected by the occurrence of these nuclear accidents. Because the acceptability of local and general residents serves as a prerequisite to nuclear power institutions and policies, increasing the social acceptability of nuclear power is important in South Korea, where the continuous use of nuclear power is necessary for the security of its nationwide energy supply and economic growth. By focusing education regarding nuclear power generation and radiation use on elementary-, middle-, and high-school students, who will, out of the general population, likely experience some of the greatest ripple effects from this focused education, the relationship between perception, knowledge, and attitude regarding nuclear power generation and radiation were then analyzed. The goals of this analysis were to help form an extensive and national social consensus regarding nuclear power generation and radiation use that is appropriate to South Korea, and improve the understanding and public perceptions of the aforementioned technology of the people of South Korea. In order for radiation technology to power national developments through the next generation, understanding and acceptance of for radiation technology by the general population must come first. In order to effectively provide data about this understanding and acceptance, elementary-, middle-, and high-school students all of whom will constitute the majority of public opinion in the near future were provided basic education regarding radiation use and nuclear power. Their perceptions before and after the intervention, as well as their knowledge and attitude as based on traditional

A Self-Powered Thin-Film Radiation Detector Using Intrinsic High-Energy Current (HEC) (Author’s Final Version)

Science.gov (United States)

2016-09-08

of electromagnetic 85 pulse effects on cables and electrical devices4 and as a self - powered detector for in-core neutron flux measurement in nuclear...AFCEC-CX-TY-TP-2016-0003 A SELF - POWERED THIN-FILM RADIATION DETECTOR USING INTRINSIC HIGH-ENERGY CURRENT (HEC) (AUTHOR’S FINAL VERSION...14 -- 5 Oct 15 A self - powered thin-film radiation detector using intrinsic high-energy current (HEC) (Author’s Final Version) FA8051-15-P-0010

Radiation effects in semiconductor laser diode arrays

International Nuclear Information System (INIS)

Carson, R.F.

1988-01-01

The effects of radiation events are important for many of the present and future applications that involve optoelectronic components. Laser diodes show a strong resistance to degradation by gamma rays, prompt x-rays and (to a lesser extent), neutrons. This is due to the short carrier lifetime that is associated with stimulated emission and the high current injection conditions that are present in these devices. Radiation-resistant properties should carry over to many of the more recently developed devices such as multi-stripe array and broad area laser diodes. There are, however, additional considerations for radiation tolerance that are introduced by these devices. Arrays and other high power laser diodes have larger active region volumes than lower power single stripe devices. In addition, evanescent field coupling between stripes, the material quality available from newer MOCVD epitaxial growth techniques, and stripe definition methods may all influence the radiation tolerance of the high power laser diode devices. Radiation tests have been conducted on various GaAs-GaAlAs laser diode array and broad area devices. Tests involving total gamma dose have indicated that high power laser diodes and arrays have small degradations in light power output with current input after 4 MRad(Si) of radiation from a Co 60 source. Additional test results involving flash x-rays indicate that high power diode lasers and arrays are tolerant to 10 12 rads(Si)/sec, when observed on microsecond or millisecond time scales. High power diode laser devices were also irradiated with neutrons to a fluence of 10 14 neutrons/cm 2 with some degradation of threshold current level

Syrinx - a research program for the pulsed power radiation facility

International Nuclear Information System (INIS)

Etlicher, B.; Chuvatin, A.S.; Choi, P.

1996-01-01

Syrinx is a targeted research program with the objective to study, through practical examples, the fundamentals necessary to define the details of all parts which will be required for a new powerful plasma radiation source. The current level of activities of Syrinx is in the design and construction of a multi-megajoule class IES based pulsed power driver which will use long conduction Plasma Opening Switch technology. The present paper reviews mainly the basic experimental research of the POS a nd Z-pinch accomplished in the framework of Syrinx project. This work has a unique international level of participation, from conceptual designs to particular investigations. (author). 9 figs., 17 refs

Full-sky formulae for weak lensing power spectra from total angular momentum method

International Nuclear Information System (INIS)

Yamauchi, Daisuke; Taruya, Atsushi; Namikawa, Toshiya

2013-01-01

We systematically derive full-sky formulae for the weak lensing power spectra generated by scalar, vector and tensor perturbations from the total angular momentum (TAM) method. Based on both the geodesic and geodesic deviation equations, we first give the gauge-invariant expressions for the deflection angle and Jacobi map as observables of the CMB lensing and cosmic shear experiments. We then apply the TAM method, originally developed in the theoretical studies of CMB, to a systematic derivation of the angular power spectra. The TAM representation, which characterizes the total angular dependence of the spatial modes projected along a line-of-sight, can carry all the information of the lensing modes generated by scalar, vector, and tensor metric perturbations. This greatly simplifies the calculation, and we present a complete set of the full-sky formulae for angular power spectra in both the E-/B-mode cosmic shear and gradient-/curl-mode lensing potential of deflection angle. Based on the formulae, we give illustrative examples of non-vanishing B-mode cosmic shear and curl-mode of deflection angle in the presence of the vector and tensor perturbations, and explicitly compute the power spectra

Ionizing radiation risks to satellite power systems (SPS) workers

International Nuclear Information System (INIS)

1980-11-01

The radiation risks to the health of workers who will construct and maintain solar power satellites in the space environment were examined. For ionizing radiation, the major concern will be late or delayed health effects, particularly the increased risk of radiation-induced cancer. The estimated lifetime risk for cancer is 0.8 to 5.0 excess deaths per 10,000 workers per rad of exposure. Thus, for example, in 10,000 workers who completed ten missions with an exposure of 40 rem per mission, 320 to 2000 additional deaths in excess of the 1640 deaths from normally occurring cancer, would be expected. These estimates would indicate a 20 to 120% increase in cancer deaths in the worker-population. The wide range in these estimates stems from the choice of the risk-projection model and the dose-response relationsip. The choice between a linear and a linear-quadratic dose-response model may alter the risk estimate by a factor of about two. The method of analysis (e.g., relative vs absolute risk model) can alter the risk estimate by an additional factor of three. Choosing different age and sex distributions can further change the estimate by another factor of up to three. The potential genetic consequences could be of significance, but at the present time, sufficient information on the age and sex distribution of the worker population is lacking for precise estimation of risk. The potential teratogenic consequences resulting from radiation are considered significant. Radiation exposure of a pregnant worker could result in developmental abnormalities

Ionizing radiation risks to satellite power systems (SPS) workers

Energy Technology Data Exchange (ETDEWEB)

Lyman, J.T.; Ainsworth, E.J.; Alpen, E.L.; Bond, V.; Curtis, S.B.; Fry, R.J.M.; Jackson, K.L.; Nachtwey, S.; Sondhaus, C.; Tobias, C.A.; Fabrikant, J.I.

1980-11-01

The radiation risks to the health of workers who will construct and maintain solar power satellites in the space environment were examined. For ionizing radiation, the major concern will be late or delayed health effects, particularly the increased risk of radiation-induced cancer. The estimated lifetime risk for cancer is 0.8 to 5.0 excess deaths per 10,000 workers per rad of exposure. Thus, for example, in 10,000 workers who completed ten missions with an exposure of 40 rem per mission, 320 to 2000 additional deaths in excess of the 1640 deaths from normally occurring cancer, would be expected. These estimates would indicate a 20 to 120% increase in cancer deaths in the worker-population. The wide range in these estimates stems from the choice of the risk-projection model and the dose-response relationsip. The choice between a linear and a linear-quadratic dose-response model may alter the risk estimate by a factor of about two. The method of analysis (e.g., relative vs absolute risk model) can alter the risk estimate by an additional factor of three. Choosing different age and sex distributions can further change the estimate by another factor of up to three. The potential genetic consequences could be of significance, but at the present time, sufficient information on the age and sex distribution of the worker population is lacking for precise estimation of risk. The potential teratogenic consequences resulting from radiation are considered significant. Radiation exposure of a pregnant worker could result in developmental abnormalities.

Status of the Development of Low Cost Radiator for Surface Fission Power - II

Science.gov (United States)

Tarau, Calin; Maxwell, Taylor; Anderson, William G.; Wagner, Corey; Wrosch, Matthew; Briggs, Maxwell H.

2016-01-01

NASA Glenn Research Center (GRC) is developing fission power system technology for future Lunar and Martian surface power applications. The systems are envisioned in the 10 to 100kWe range and have an anticipated design life of 8 to 15 years with no maintenance. NASA GRC is currently setting up a 55 kWe non-nuclear system ground test in thermal-vacuum to validate technologies required to transfer reactor heat, convert the heat into electricity, reject waste heat, process the electrical output, and demonstrate overall system performance. The paper reports on the development of the heat pipe radiator to reject the waste heat from the Stirling convertors. Reducing the radiator mass, size, and cost is essential to the success of the program. To meet these goals, Advanced Cooling Technologies, Inc. (ACT) and Vanguard Space Technologies, Inc. (VST) are developing a single facesheet radiator with heat pipes directly bonded to the facesheet. The facesheet material is a graphite fiber reinforced composite (GFRC) and the heat pipes are titanium/water Variable Conductance Heat Pipes (VCHPs). By directly bonding a single facesheet to the heat pipes, several heavy and expensive components can be eliminated from the traditional radiator design such as, POCO"TM" foam saddles, aluminum honeycomb, and a second facesheet. As mentioned in previous papers by the authors, the final design of the waste heat radiator is described as being modular with independent GFRC panels for each heat pipe. The present paper reports on test results for a single radiator module as well as a radiator cluster consisting of eight integral modules. These tests were carried out in both ambient and vacuum conditions. While the vacuum testing of the single radiator module was performed in the ACT's vacuum chamber, the vacuum testing of the eight heat pipe radiator cluster took place in NASA GRC's vacuum chamber to accommodate the larger size of the cluster. The results for both articles show good agreement

Tetrode bias power supply for Indus-1, synchrotron radiation source

International Nuclear Information System (INIS)

Tripathi, A.; Badapanda, M.K.; Tyagi, R.; Upadhyay, R.; Bohrey, A.; Hannurkar, P.R.

2009-01-01

An AC regulator based 7 kV, 3 A high voltage DC power supply is designed, fabricated and tested on dummy load for BEL make Tetrode type 15000CX, used in the high power RF amplifier at 31.613 MHz employed with INDUS-1, Synchrotron Radiation Source (SRS). Various protections features like over voltage, under voltage, over current, phase failure and phase reversal are incorporated in this power supply and presented in this paper. As Tetrode amplifier requires various other power supplies in addition to this bias power supply and they are operated in a particular sequence for its healthy operation, suitable interlock arrangements have been incorporated and also presented in this paper. The reliable operation of protection and interlock features incorporated in this power supply has been checked with dummy load under simulated conditions. Three numbers of series limiting inductors, one in each phase, have been incorporated in this power supply to limit fault currents under unfavourable conditions and there by increasing the overall life of this power supply. It will replace existing 7 kV, 3 A HVDC power supply, which is in operation for more than fifteen years with Indus-1 SRS and is likely to be helpful in reducing the down time of Indus-1 SRS. It has better performance features than the existing power supply. The long term voltage stability better than 0.3 % and output ripple less than 0.3 % have been achieved for this Tetrode bias power supply. This power supply is likely to be integrated with INDUS-1 SRS soon. (author)

Commercial power silicon devices as possible routine dosimeters for radiation processing

International Nuclear Information System (INIS)

Fuochi, P.G.; Lavalle, M.; Gombia, E.; Mosca, R.; Kovacs, A.V.; Hargittai, P.; Vitanza, A.; Patti, A.

2001-01-01

The use of silicon devices as possible radiation dosimeters has been investigated in this study. A bipolar power transistor in TO126 plastic packaging has been selected. Irradiations, with doses in the range from 50 Gy up to 5 kGy, have been performed at room temperature using different radiation sources ( 60 Co g source, 2.5, 4 and 12 MeV electron accelerators). Few irradiations with g rays were also done at different temperatures. A physical parameter, T, related to the charge carrier lifetime, has been found to change as a function of irradiation dose. This change is radiation energy dependent. Long term stability of the electron irradiated transistors has been checked by means of a reliability test ('high temperature reverse bias', HTRB) at 150 deg. C for 1000 h. Deep level transient spectroscopy (DLTS) measurements have been performed on the irradiated devices to identify the recombination centres introduced by the radiation treatment. The results obtained confirm that these transistors could be used as routine radiation dosimeters in a certain dose range. More work needs to be done particularly with g rays in the low dose region (50-200 Gy) and with low energy electrons. (author)

Inhaled /sup 147/Pm and/or total-body gamma radiation: Early mortality and morbidity in rats

Energy Technology Data Exchange (ETDEWEB)

Filipy, R.E.; Lauhala, K.E.; McGee, D.R.; Cannon, W.C.; Buschbom, R.L.; Decker, J.R.; Kuffel, E.G.; Park, J.F.; Ragan, H.A.; Yaniv, S.S.; Scott, B.R.

1989-05-01

Rats were given doses of /sup 60/Co gamma radiation and/or lung burdens of /sup 147/Pm (in fused aluminosilicate particles) within lethal ranges in an experiment to determine and compare morbidity and mortality responses for the radiation insults within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Acute mortality and morbidity from inhaled promethium were caused primarily by radiation pneumonitis and pulmonary fibrosis that occurred more than 53 days after exposure. Acute mortality and morbidity from total-body gamma irradiation occurred within 30 days of exposure and resulted from the bone-marrow radiation syndrome. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell levels and by reduced body weight gain in animals that survived the acute gamma radiation syndrome. Inhaled promethium caused a loss of body weight and diminished pulmonary function, but its only effect on blood cell levels was lymphocytopenia. Combined gamma irradiation and promethium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Promethium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the later effect of promethium lung burdens. 70 refs., 68 figs., 21 tabs.

Solar radiation - to - power generation models for one-axis tracking PV system with on-site measurements from Eskisehir, Turkey

Science.gov (United States)

Filik, Tansu; Başaran Filik, Ümmühan; Nezih Gerek, Ömer

2017-11-01

In this study, new analytic models are proposed for mapping on-site global solar radiation values to electrical power output values in solar photovoltaic (PV) panels. The model extraction is achieved by simultaneously recording solar radiation and generated power from fixed and tracking panels, each with capacity of 3 kW, in Eskisehir (Turkey) region. It is shown that the relation between the solar radiation and the corresponding electric power is not only nonlinear, but it also exhibits an interesting time-varying characteristic in the form of a hysteresis function. This observed radiation-to-power relation is, then, analytically modelled with three piece-wise function parts (corresponding to morning, noon and evening times), which is another novel contribution of this work. The model is determined for both fixed panels and panels with a tracking system. Especially the panel system with a dynamic tracker produces a harmonically richer (with higher values in general) characteristic, so higher order polynomial models are necessary for the construction of analytical solar radiation models. The presented models, characteristics of the hysteresis functions, and differences in the fixed versus solar-tracking panels are expected to provide valuable insight for further model based researches.

Low-power millimeter wave radiations do not alter stress-sensitive gene expression of chaperone proteins.

Science.gov (United States)

Zhadobov, M; Sauleau, R; Le Coq, L; Debure, L; Thouroude, D; Michel, D; Le Dréan, Y

2007-04-01

This article reports experimental results on the influence of low-power millimeter wave (MMW) radiation at 60 GHz on a set of stress-sensitive gene expression of molecular chaperones, namely clusterin (CLU) and HSP70, in a human brain cell line. Selection of the exposure frequency is determined by its near-future applications for the new broadband civil wireless communication systems including wireless local area networks (WLAN) for domestic and professional uses. Frequencies around 60 GHz are strongly attenuated in the earth's atmosphere and such radiations represent a new environmental factor. An exposure system operating in V-band (50-75 GHz) was developed for cell exposure. U-251 MG glial cell line was sham-exposed or exposed to MMW radiation for different durations (1-33 h) and two different power densities (5.4 microW/cm(2) or 0.54 mW/cm(2)). As gene expression is a multiple-step process, we analyzed chaperone proteins induction at different levels. First, using luciferase reporter gene, we investigated potential effect of MMWs on the activation of transcription factors (TFs) and gene promoter activity. Next, using RT-PCR and Western blot assays, we verified whether MMW exposure could alter RNA accumulation, translation, or protein stability. Experimental data demonstrated the absence of significant modifications in gene transcription, mRNA, and protein amount for the considered stress-sensitive genes for the exposure durations and power densities investigated. The main results of this study suggest that low-power 60 GHz radiation does not modify stress-sensitive gene expression of chaperone proteins. (c) 2006 Wiley-Liss, Inc.

Generic study on the design and operation of high power targets

Directory of Open Access Journals (Sweden)

A. Ahmad

2014-02-01

Full Text Available With the move towards beam power in the range of 1–10 MW, a thorough understanding of the response of target materials and auxiliary systems to high power densities and intense radiation fields is required. This paper provides insight into three major aspects related to the design and operation of high power solid targets: thermal stresses, coolant performance, and radiation damage. Where appropriate, a figure-of-merit approach is followed to facilitate the comparison between different target or coolant candidates. The section on radiation damage reports total and spatial variations of displacement-per-atom and helium production levels in different target materials.

Application of a Pelletron accelerator to study total dose radiation effects on 50 GHz SiGe HBTs

Energy Technology Data Exchange (ETDEWEB)

Praveen, K.C.; Pushpa, N.; Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Tripathi, Ambuj [Inter University Accelerator Centre (IUAC), New Delhi 110 067 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Total dose effects of 50 MeV Li3+ ion on 50 GHz SiGe HBTs is investigated. Black-Right-Pointing-Pointer Ion irradiated results were compared with Co-60 gamma results. Black-Right-Pointing-Pointer 50 MeV Li ions create more damage in E-B spacer oxide when compared to Co-60 gamma radiation. Black-Right-Pointing-Pointer Co-60 gamma radiation create more damage in STI oxide when compared to 50 MeV Li ions. Black-Right-Pointing-Pointer Worst case total dose radiation effects can be studied using Pelletron accelerator facilities. - Abstract: We have investigated the effects of 50 MeV lithium ion irradiation on the DC electrical characteristics of first-generation silicon-germanium heterojunction bipolar transistors (50 GHz SiGe HBTs) in the dose range of 600 krad to 100 Mrad. The results of 50 MeV Li{sup 3+} ion irradiation on the SiGe HBTs are compared with 63 MeV proton and Co-60 gamma irradiation results in the same dose range in order to understand the damage induced by different LET species. The radiation response of emitter-base (EB) spacer oxide and shallow trench isolation (STI) oxide to different irradiation types are discussed in this paper. We have also focused on the efficacy in the application of a Pelletron accelerator to study total dose irradiation studies in SiGe HBTs.

Cost Savings of Nuclear Power with Total Fuel Reprocessing

International Nuclear Information System (INIS)

Solbrig, Charles W.; Benedict, Robert W.

2006-01-01

The cost of fast reactor (FR) generated electricity with pyro-processing is estimated in this article. It compares favorably with other forms of energy and is shown to be less than that produced by light water reactors (LWR's). FR's use all the energy in natural uranium whereas LWR's utilize only 0.7% of it. Because of high radioactivity, pyro-processing is not open to weapon material diversion. This technology is ready now. Nuclear power has the same advantage as coal power in that it is not dependent upon a scarce foreign fuel and has the significant additional advantage of not contributing to global warming or air pollution. A jump start on new nuclear plants could rapidly allow electric furnaces to replace home heating oil furnaces and utilize high capacity batteries for hybrid automobiles: both would reduce US reliance on oil. If these were fast reactors fueled by reprocessed fuel, the spent fuel storage problem could also be solved. Costs are derived from assumptions on the LWR's and FR's five cost components: 1) Capital costs: LWR plants cost $106/MWe. FR's cost 25% more. Forty year amortization is used. 2) The annual O and M costs for both plants are 9% of the Capital Costs. 3) LWR fuel costs about 0.0035 $/kWh. Producing FR fuel from spent fuel by pyro-processing must be done in highly shielded hot cells which is costly. However, the five foot thick concrete walls have the advantage of prohibiting diversion. LWR spent fuel must be used as feedstock for the FR initial core load and first two reloads so this FR fuel costs more than LWR fuel. FR fuel costs much less for subsequent core reloads ( 6 /MWe. The annual cost for a 40 year licensed plant would be 2.5 % of this or less if interest is taken into account. All plants will eventually have to replace those components which become radiation damaged. FR's should be designed to replace parts rather than decommission. The LWR costs are estimated to be 2.65 cents/kWh. FR costs are 2.99 cents/kWh for the first

Nuclear energy and radiation

International Nuclear Information System (INIS)

Myers, D.K.; Johnson, J.R.

1980-01-01

Both the light water reactor and the Canadian heavy water reactor systems produce electricity cheaply and efficiently. They produce some fissionable byproducts, which can be recycled to extend energy sources many-fold. Besides the production of electrical power, the nuclear industry produces various radioistopes used for treatment of cancer, in diagnostic procedures in nuclear medicine, in ionization smoke detectors, and as radioactive tracers with various technological applications including the study of the mechanisms of life. The increment in environmental radiation levels resulting from operation of nuclear power reactors represents a very small fraction of the radiation levels to which we are all exposed from natural sources, and of the average radiation exposures resulting from diagnostic procedures in the healing arts. The total health hazard of the complete nuclear power cycle is generally agreed to be smaller than the hazards associated with the generation of an equal amount of electricity from most other currently available sources of energy. The hazards from energy production in terms of shortened life expectancy are much smaller in all cases than the resulting increase in health and life expectancy. (auth)

Ways of reducing radiation exposure in a future nuclear power economy

International Nuclear Information System (INIS)

Morgan, K.Z.

1976-01-01

The reasons for attempting to reduce radiation exposure in a future nuclear power economy are first discussed. This is followed by a detailed examination of ways for reducing exposures. The entire fuel cycle from uranium mining through fuel reprocessing is covered but special attention is devoted to reactors, fuel and waste shipping and fuel reprocessing

Low-level radiation

International Nuclear Information System (INIS)

Myers, D.K.

1982-05-01

It is known that the normal incidence of cancer in human populations is increased by exposure to moderately high doses of ionizing radiation. At background radiation levels or at radiation levels which are 100 times greater, the potential health risks are considered to be directly proportional to the total accumulated dose of radiation. Some of the uncertainties associated with this assumption and with the accepted risk estimates have been critically reviewed in this document. The general scientific consensus at present suggests that the accepted risk estimates may exaggerate the actual risk of low levels of sparsely ionizing radiations (beta-, gamma- or X-rays) somewhat but are unlikely to overestimate the actual risks of densely ionizing radiations (fast neutrons, alpha-particles). At the maximum permissible levels of exposure for radiation workers in nuclear power stations, the potential health hazards in terms of life expectancy would be comparable to those encountered in transportation and public utilities or in the construction industry. At the average radiation exposures received by these workers in practice, the potential health hazards are similar to those associated with safe categories of industries. Uranium mining remains a relativly hazardous occupation. In terms of absolute numbers, the genetic hazards, which are less well established, are thought to be smaller than the carcinogenic hazards of radiation when only the first generation is considered but to be of the same order of magnitude as the carcinogenic hazards when the total number of induced genetic disorders is summed over all generations

Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

International Nuclear Information System (INIS)

Fehringer, F.; Seitz, G.; Hammer, G.P.; Blettner, M.

2006-01-01

A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

Energy Technology Data Exchange (ETDEWEB)

Fehringer, F.; Seitz, G. [Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Koln (Germany); Hammer, G.P.; Blettner, M. [Johannes Gutenberg-Universitat Mainz, Institut fur Medizinische Biometrie, Epidemiologie und Informatik des Klinikums (Germany)

2006-07-01

A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

Radiation therapy for angiosarcoma of the scalp: treatment outcomes of total scalp irradiation with X-rays and electrons.

Science.gov (United States)

Hata, Masaharu; Wada, Hidefumi; Ogino, Ichiro; Omura, Motoko; Koike, Izumi; Tayama, Yoshibumi; Odagiri, Kazumasa; Kasuya, Takeo; Inoue, Tomio

2014-10-01

Wide surgical excision is the standard treatment for angiosarcoma of the scalp, but many patients are inoperable. Therefore, we investigated the outcome of radiation therapy for angiosarcoma of the scalp. Seventeen patients with angiosarcoma of the scalp underwent radiation therapy with total scalp irradiation. Four patients had cervical lymph node metastases, but none had distant metastases. A median initial dose of 50 Gy in 25 fractions was delivered to the entire scalp. Subsequently, local radiation boost to the tumor sites achieved a median total dose of 70 Gy in 35 fractions. Fourteen of the 17 patients developed recurrences during the median follow-up period of 14 months after radiation therapy; 7 had recurrences in the scalp, including primary tumor progression in 2 patients and new disease in 5, and 12 patients developed distant metastases. The primary progression-free, scalp relapse-free, and distant metastasis-free rates were 86, 67, and 38 % at 1 year and 86, 38, and 16 % at 3 years, respectively. Thirteen patients died; the overall and cause-specific survival rates were both 73 % at 1 year and 23 and 44 % at 3 years, respectively. The median survival time was 16 months. There were no therapy-related toxicities ≥ grade 3. Total scalp irradiation is safe and effective for local tumor control, but a dose of ≤ 50 Gy in conventional fractions may be insufficient to eradicate microscopic tumors. For gross tumors, a total dose of 70 Gy, and > 70 Gy for tumors with deep invasion, is recommended.

Soil radioactivity levels and radiation hazard assessment around a Thermal Power Plant

International Nuclear Information System (INIS)

Kumar, Mukesh; Kumar, Pankaj; Sharma, Somdutt; Agrawal, Anshu; Kumar, Rajesh; Prajith, Rama; Sahoo, B.K.

2016-01-01

Coal based thermal power plants further enhance the level of radioactivity in the environment, as burning of coal produces fly ash that can be released into the environment containing traces of 238 U, 232 Th and their decay products. Therefore, coal fired power plants are one of the major contributor towards the Technologically Enhanced Natural Radiation (TENR). Keeping this in view, a study of natural radioactivity in the soil of twenty five villages within 5 km radius around the Harduaganj Thermal Power Plant, Aligarh, UP, India is going on under a BRNS major project, to know the radiological implications on general population living around this plant

Approach to reducing the effect of bone—coal power station on radiation environment

Institute of Scientific and Technical Information of China (English)

NIShi－Ying; GUPei－Long; 等

2002-01-01

The effect of two bone-coal power stations(6MWe) on environment was investigated within the scope of the dose contribution caused by various radionucildes in different ways.It is found that the best measures to reduce the effect of bone-coal power station on radiation environment include to select a fine boiler system and a comprehensive utilization of the bone-coal cinder(BCC),soot and ash in the catchers.

Approach to reducing the effect of bone-coal power station on radiation environment

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

The effect of two bone-coal power stations (6 MWe) on environment wasinvestigated within the scope of the dose contribution caused by various radionucildes in different ways. It is found that the best measures to reduce the effect of bone-coal power station on radiation environment include to select a fine boiler system and a comprehensive utilization of the bone-coal cinder (BCC), soot and ash in the catchers.

A general method for computing the total solar radiation force on complex spacecraft structures

Science.gov (United States)

Chan, F. K.

1981-01-01

The method circumvents many of the existing difficulties in computational logic presently encountered in the direct analytical or numerical evaluation of the appropriate surface integral. It may be applied to complex spacecraft structures for computing the total force arising from either specular or diffuse reflection or even from non-Lambertian reflection and re-radiation.

Effect of Different Solar Radiation Data Sources on the Variation of Techno-Economic Feasibility of PV Power System

Science.gov (United States)

Alghoul, M. A.; Ali, Amer; Kannanaikal, F. V.; Amin, N.; Aljaafar, A. A.; Kadhim, Mohammed; Sopian, K.

2017-11-01

The aim of this study is to evaluate the variation in techno-economic feasibility of PV power system under different data sources of solar radiation. HOMER simulation tool is used to predict the techno-economic feasibility parameters of PV power system in Baghdad city, Iraq located at (33.3128° N, 44.3615° E) as a case study. Four data sources of solar radiation, different annual capacity shortages percentage (0, 2.5, 5, and 7.5), and wide range of daily load profile (10-100 kWh/day) are implemented. The analyzed parameters of the techno-economic feasibility are COE (/kWh), PV array power capacity (kW), PV electrical production (kWh/year), No. of batteries and battery lifetime (year). The main results of the study revealed the followings: (1) solar radiation from different data sources caused observed to significant variation in the values of the techno-economic feasibility parameters; therefore, careful attention must be paid to ensure the use of an accurate solar input data; (2) Average solar radiation from different data sources can be recommended as a reasonable input data; (3) it is observed that as the size and of PV power system increases, the effect of different data sources of solar radiation increases and causes significant variation in the values of the techno-economic feasibility parameters.

The total ozone and UV solar radiation over Stara Zagora, Bulgaria

Science.gov (United States)

Mendeva, B. D.; Gogosheva, Ts. N.; Petkov, B. H.; Krastev, D. G.

The results from direct ground-based solar UV irradiance measurements and the total ozone content (TOC) over Stara Zagora (42° 25'N, 25° 37'E), Bulgaria are presented. During the period 1999-2003 the TOC data show seasonal variations, typical for the middle latitudes - maximum in the spring and minimum in the autumn. The comparison between TOC ground-based data and Global Ozone Monitoring Experiment (GOME) satellite-borne ones shows a seasonal dependence of the differences between them. A strong negative relationship between the total ozone and the 305 nm wavelength irradiance was found. The dependence between the two variables is significant ( r = -0.62 ± 0.18) at 98% confidence level. The direct sun UV doses for some specific biological effects (erythema and eyes) are obtained. The estimation of the radiation amplification factor RAF shows that the ozone reduction by 1% increases the erythemal dose by 2.3%. The eye-damaging doses are more influenced by the TOC changes and in this case RAF = -2.7%. The amount of these biological doses depended on the solar altitude over the horizon. This dependence was not so strong when the total ozone content in the atmosphere was lower.

An adaptive crystal bender for high power synchrotron radiation beams

International Nuclear Information System (INIS)

Berman, L.E.; Hastings, J.B.

1992-01-01

Perfect crystal monochromators cannot diffract x-rays efficiently, nor transmit the high source brightness available at synchrotron radiation facilities, unless surface strains within the beam footprint are maintained within a few arcseconds. Insertion devices at existing synchrotron sources already produce x-ray power density levels that can induce surface slope errors of several arcseconds on silicon monochromator crystals at room temperature, no matter how well the crystal is cooled. The power density levels that will be produced by insertion devices at the third-generation sources will be as much as a factor of 100 higher still. One method of restoring ideal x-ray diffraction behavior, while coping with high power levels, involves adaptive compensation of the induced thermal strain field. The design and performance, using the X25 hybrid wiggler beam line at the National Synchrotron Light Source (NSLS), of a silicon crystal bender constructed for this purpose are described

On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: I. Cosmic microwave background radiation

Science.gov (United States)

Fisenko, Anatoliy I.; Lemberg, Vladimir

2014-07-01

Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v 1≤ v≤ v 2 are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60-600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.

Radiation monitoring handbook for visits by nuclear powered warships to Australian ports

Energy Technology Data Exchange (ETDEWEB)

Woods, D.A

1995-09-01

The purpose of this handbook is to detail the Radiation Monitoring (RMG) roles and procedures, and to provide technical and background information useful to RMG personnel. It has been written on the assumption that all members of the RMG have had appropriate radiation safety (Health Physics) training. Separate standing procedures, for both routine and emergency activities, are required for each port. These are incorporated in Port Safety Plans and specify the routine monitoring requirements for individual berths or anchorages and the procedures to be followed after indication of a reactor accident to a nuclear powered warship. A Visit Operation Order, issued for each Nuclear Powered warships (NPW) visit, presents information specific to that visit. Routine monitoring is performed to confirm normal conditions. The objectives of emergency radiation monitoring are: to provide early detection of a reactor accident of sufficient severity to possibly cause a major release of fission products to the environment; to determine the nature and extent of any fission product release; to provide information to assist in evaluating the accident; to assess the need and extent of required countermeasures; and to determine when the release has terminated and when affected areas have returned to normal Prepared on behalf of the Visiting Ship Panel (Nuclear), Department of Defence; 11 refs., 11 tabs., 21 figs.

Design and development of Solar Powered Wireless Telemetering System (SPWTS) for Environmental Radiation Monitoring (ERM) of nuclear power plants

International Nuclear Information System (INIS)

Mariappan, Bhuvaneswari; Ramachandran, Shanmugalakshmi

2014-01-01

Presently, the real time environmental radiation monitoring system installed in the nuclear power plant is based on LAN. Generally data from the surveillance instrument are collected at regular intervals using a lap-top or system/units and taken to the laboratory for downloading the archival data. So a need was felt to design and develop Solar powered Wireless Telemetering System (SPWTS) for Environmental Radiation Monitoring (ERM) of Nuclear Power Plants. SPWTS is used for real-time monitoring and wireless transmission of the on-line data to the Central Control Unit (CCU) to investigate the history of monitored data. Thus, in this paper a wireless mode using Zigbee is proposed, thereby improving scalability, flexibility and continuous radiological surveillance along with data archival facility. The proposed Solar Powered Wireless Telemetering System (SPWTS) comprising of transmitter, intermediate devices and receiver units transmits the ERM data to Central Control Unit (CCU) for storage and display to RADAS unit. In order to meet the coverage distance without data loss, suitable number of repeaters/routers are configured and joined in the network. The entire wireless telemetry system is powered up by solar cells with rechargeable battery backup facility, SPWTS suitable for ERM data transmission module will replace the wired Ethernet environment by wireless mode thereby improving scalability, flexibility and continuous radiological surveillance of the gamma dose monitoring. This module also proposes solutions for wireless transmission of safety related critical data to a remote control unit. Finally, this module promotes interoperability within hierarchical framework by reducing the amount of changes that could be introduced into the existing system. (author)

Total dose radiation effects of pressure sensors fabricated on uni-bond-SOI materials

International Nuclear Information System (INIS)

Zhu Shiyang; Huang Yiping; Wang Jin; Li Anzhen; Shen Shaoqun; Bao Minhang

2001-01-01

Piezoresistive pressure sensors with a twin-island structure were successfully fabricated using high quality Uni-bond-SOI (On Insulator) materials. Since the piezoresistors were structured by the single crystalline silicon overlayer of the SOI wafer and were totally isolated by the buried SiO 2 , the sensors are radiation-hard. The sensitivity and the linearity of the pressure sensors keep their original values after being irradiated by 60 Co γ-rays up to 2.3 x 10 4 Gy(H 2 O). However, the offset voltage of the sensor has a slight drift, increasing with the radiation dose. The absolute value of the offset voltage deviation depends on the pressure sensor itself. For comparison, corresponding polysilicon pressure sensors were fabricated using the similar process and irradiated at the same condition

Utilisation of total solar radiation energy in the photosynthetic production of radish, red beet and bean

Directory of Open Access Journals (Sweden)

Wiesław Nowakowski

2014-01-01

Full Text Available Utilisation of total solar radiation energy in the photosynthetic production of radish, red beet and bean is expressed as per cent of solar radiation accumulated in the carbon of -the dry mass per 1 cm2 of the assimilation surface area. Utilisation of this energy ranges from 2.6 to 8.4 per cent in radish, from 1.7 to 7.5 per cent in beet and from 1.9 to 4.9 per cent in bean.

Materials-of-Construction Radiation Sensitivity for a Fission Surface Power Convertor

Science.gov (United States)

Bowman, Cheryl L.; Geng, Steven M.; Niedra, Janis M.; Sayir, Ali; Shin, Eugene E.; Sutter, James K.; Thieme, Lanny G.

2007-01-01

A fission reactor combined with a free-piston Stirling convertor is one of many credible approaches for producing electrical power in space applications. This study assumes dual-opposed free-piston Stirling engines/linear alternators that will operate nominally at 825 K hot-end and 425 K cold-end temperatures. The baseline design options, temperature profiles, and materials of construction discussed here are based on historical designs as well as modern convertors operating at lower power levels. This notional design indicates convertors primarily made of metallic components that experience minimal change in mechanical properties for fast neutron fluences less than 10(sup 20) neutrons per square centimeter. However, these radiation effects can impact the magnetic and electrical properties of metals at much lower fluences than are crucial for mechanical property integrity. Moreover, a variety of polymeric materials are also used in common free-piston Stirling designs for bonding, seals, lubrication, insulation and others. Polymers can be affected adversely by radiation doses as low as 10(sup 5) - 10(sup 10) rad. Additionally, the absorbing dose rate, radiation hardness, and the resulting effect (either hardening or softening) varies depending on the nature of the particular polymer. The classes of polymers currently used in convertor fabrication are discussed along possible substitution options. Thus, the materials of construction of prototypic Stirling convertor engines have been considered and the component materials susceptible to damage at the lowest neutron fluences have been identified.

Assessment of nuclear power sources in Czechoslovakia with respect to radiation protection limits

International Nuclear Information System (INIS)

Melichar, Z.

1985-01-01

The principles are presented which underlie the determination of limits of planned population exposure during normal operation of nuclear installations and of reference levels of exceptional population exposure during nuclear power plant accidents. The introduction is discussed of authorized limits and levels in Czechoslovakia the USSR, CMEA countries and Sweden. An estimate is made of the radiation burden of the population during the development of the Czechoslovak nuclear power programme. (E.S.)

Use of complex electronic equipment within radiative areas of PWR power plants: feability study

International Nuclear Information System (INIS)

Fremont, P.; Carquet, M.

1988-01-01

EDF has undertaken a study in order to evaluate the technical and economical feasibility of using complex electronic equipment within radiative areas of PWR power plants. This study lies on tests of VLSI components (Random Access Memories) under gamma rays irradiations, which aims are to evaluate the radiation dose that they can withstand and to develop a selection method. 125 rad/h and 16 rad/h tests results are given [fr

Compression and radiation of high-power short rf pulses. II. A novel antenna array design with combined compressor/radiator elements

KAUST Repository

Sirenko, Kostyantyn; Pazynin, Vadim L.; Sirenko, Yu K.; Bagci, Hakan

2011-01-01

The paper discusses the radiation of compressed high power short RF pulses using two different types of antennas: (i) A simple monopole antenna and (ii) a novel array design, where each of the elements is constructed by combining a compressor and a

Low power laser effects in cancer cells and fibroblasts submitted the ionizing radiation

International Nuclear Information System (INIS)

Silva, Camila Ramos

2015-01-01

Cancer is considered a public health problem worldwide. According to Brazil's the National Cancer Institute (INCA), 576,000 new cases of cancer were estimated for 2015 in Brazil, representing the second leading cause of death. Radiotherapy may be a treatment to several of types of cancer, frequently using ionizing radiation to eradicate or prevent the proliferation of tumor cells. This treatment, however, can lead to death of non-tumor cells around in irradiated tissue. Given this, adjuvant therapies that can minimize the side effects of ionizing radiation are of extremely importance. In this context, low power laser (LPL) may be an alternative to modulate the response of healthy cells to ionizing radiation. In this study, cells of human gingival fibroblasts (FMM1) and breast cancer (MDAMB- 231) were exposed to gamma radiation at doses of 2.5 and 10 Gy. After twenty-four hours, cell were irradiated with LPL ( λ= 660 nm, 40 mW and total area of 0.04 cm²) with energy densities of 30, 60, 90, 120 and 150 J/cm². The cell viability was measured during four days, using the trypan blue technique. The influence of LPL on the cell cycle and on expression of the nuclear antigen of cellular proliferation (PCNA) was evaluated by flow cytometry. The expression of β-Galactosidase was the chosen method to assess cell senescence. Considering our adopted parameters, and focusing on the non-tumor cells, we have observed an increase in: 1) cell viability; 2) cell population in phases S and G 2 /M cell cycle; 3) PCNA expression with decrease in senescence. No alterations were observed in the cell viability, with greater population in phases S and G 2 /M cell cycle, while the number of senescent cells and the expression of PCNA were decreased. Therefore, we have concluded that the LPL promoted effects on both cell lineages, with increased cell viability on FMM1 cells, whether cancer cells maintained a decreased proliferation. (author)

Power reactor services provided by the Penn State Radiation Science and Engineering Center

International Nuclear Information System (INIS)

Voth, M.H.; Jester, W.A.

1993-01-01

The power reactor industry emerged from extensive research and development performed at nonpower reactors (NPRs). As the industry matures, NPRs continue to support and enhance power reactor technology. With the closure of many government and private industry NPRS, there is an increasing call for the 33 universities with operating research reactors to provide the needed services. The Penn State Radiation Science and Engineering Center (RSEC) includes a 1-MW pool-type pulsing TRIGA reactor, a neutron beam laboratory with real-time neutron radiography equipment, hot cells with master-slave manipulators for remote handling of radioactive materials, a gamma-ray irradiation pool, a low-level radiation monitoring laboratory, and extensive equipment for radiation monitoring, dosimetry, and material properties determination. While equipment is heavily utilized in the instructional and academic research programs, significant time remains available for service work. Cost recovery for service work generates income for personnel, equipment maintenance, and facility improvements. With decreasing federal and state funding for educational programs, it is increasingly important that facilities be fully utilized to generate supplementary revenue. The following are examples of such work performed at the RSEC

Mobile telephones: a comparison of radiated power between 3G VoIP calls and 3G VoCS calls.

Science.gov (United States)

Jovanovic, Dragan; Bragard, Guillaume; Picard, Dominique; Chauvin, Sébastien

2015-01-01

The purpose of this study is to assess the mean RF power radiated by mobile telephones during voice calls in 3G VoIP (Voice over Internet Protocol) using an application well known to mobile Internet users, and to compare it with the mean power radiated during voice calls in 3G VoCS (Voice over Circuit Switch) on a traditional network. Knowing that the specific absorption rate (SAR) is proportional to the mean radiated power, the user's exposure could be clearly identified at the same time. Three 3G (High Speed Packet Access) smartphones from three different manufacturers, all dual-band for GSM (900 MHz, 1800 MHz) and dual-band for UMTS (900 MHz, 1950 MHz), were used between 28 July and 04 August 2011 in Paris (France) to make 220 two-minute calls on a mobile telephone network with national coverage. The places where the calls were made were selected in such a way as to describe the whole range of usage situations of the mobile telephone. The measuring equipment, called "SYRPOM", recorded the radiation power levels and the frequency bands used during the calls with a sampling rate of 20,000 per second. In the framework of this study, the mean normalised power radiated by a telephone in 3G VoIP calls was evaluated at 0.75% maximum power of the smartphone, compared with 0.22% in 3G VoCS calls. The very low average power levels associated with use of 3G devices with VoIP or VoCS support the view that RF exposure resulting from their use is far from exceeding the basic restrictions of current exposure limits in terms of SAR.

Critical coupling of surface plasmons in graphene attenuated total reflection geometry

Energy Technology Data Exchange (ETDEWEB)

Cuevas, Mauro, E-mail: cuevas@df.uba.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Facultad de Ingeniería y Tecnología Informática, Universidad de Belgrano, Villanueva 1324, C1426BMJ, Buenos Aires (Argentina); Grupo de Electromagnetismo Aplicado, Departamento de Física, FCEN, Universidad de Buenos Aires and IFIBA, Ciudad Universitaria, Pabellón I, C1428EHA, Buenos Aires (Argentina)

2016-12-09

We study the optical response of an attenuated total reflection (ATR) structure in Otto configuration with graphene sheet, paying especial attention to the occurrence of total absorption. Our results show that due to excitation of surface plasmons on the graphene sheet, two different conditions of total absorption may occur. At these conditions, the energy loss of the surface plasmon by radiation is equal to its energy loss by absorption into the graphene sheet. We give necessary conditions on ATR parameters for the existence of total absorption. - Highlights: • Attenuated total reflection (ATR) structure with graphene sheet. • Surface plasmons and power matched condition. • Necessary conditions on ATR parameters for the existence of total absorption.

Critical coupling of surface plasmons in graphene attenuated total reflection geometry

International Nuclear Information System (INIS)

Cuevas, Mauro

2016-01-01

We study the optical response of an attenuated total reflection (ATR) structure in Otto configuration with graphene sheet, paying especial attention to the occurrence of total absorption. Our results show that due to excitation of surface plasmons on the graphene sheet, two different conditions of total absorption may occur. At these conditions, the energy loss of the surface plasmon by radiation is equal to its energy loss by absorption into the graphene sheet. We give necessary conditions on ATR parameters for the existence of total absorption. - Highlights: • Attenuated total reflection (ATR) structure with graphene sheet. • Surface plasmons and power matched condition. • Necessary conditions on ATR parameters for the existence of total absorption.

Galileon radiation from a spherical collapsing shell

Energy Technology Data Exchange (ETDEWEB)

Martín-García, Javier [Instituto de Física Teórica UAM/CSIC,C/ Nicolás Cabrera 15, E-28049 Madrid (Spain); Vázquez-Mozo, Miguel Á. [Instituto Universitario de Física Fundamental y Matemáticas (IUFFyM),Universidad de Salamanca, Plaza de la Merced s/n, E-37008 Salamanca (Spain)

2017-01-17

Galileon radiation in the collapse of a thin spherical shell of matter is analyzed. In the framework of a cubic Galileon theory, we compute the field profile produced at large distances by a short collapse, finding that the radiated field has two peaks traveling ahead of light fronts. The total energy radiated during the collapse follows a power law scaling with the shell’s physical width and results from two competing effects: a Vainshtein suppression of the emission and an enhancement due to the thinness of the shell.

Radiation protection actions at Swedish nuclear power plants 1994-2002 and some reflections about the near future

International Nuclear Information System (INIS)

Erixon, Stig; Godaas, Tommy; Hofvander, Peter; Lund, Ingmar; Malmqvist, Lars; Thimgren, Ingela; Oelander-Guer, Hanna

2003-12-01

This report provides a summary of radiation protection experiences over the years 1994-2002 in the Swedish nuclear power industry. Actions to reduce radiation levels in reactor systems, occupational exposure results and some reflections about the near future are presented

Occupational radiation exposure at commercial nuclear power reactors and other facilities 1992. Twenty-fifth annual report, Volume 14

International Nuclear Information System (INIS)

Raddatz, C.T.

1993-12-01

This report summarizes the occupational radiation exposure information that has been reported to the NRC's Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC licensees during the years 1969 through 1992. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10CFR20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC licensed facilities were obtained from reports submitted pursuant to 10CFR20.408. The 1992 annual reports submitted by about 364 licensees indicated that approximately 204,365 individuals were monitored, 183,927 of whom were monitored by nuclear power facilities. They incurred an average individual dose of 0.16 rem (cSv) and an average measurable dose of about 0.30 (cSv). Termination radiation exposure reports were analyzed to reveal that about 74,566 individuals completed their employment with one or more of the 364 covered licensees during 1992. Some 71,846 of these individuals terminated from power reactor facilities, and about 9,724 of them were considered to be transient workers who received an average dose of 0.50 rem (cSv)

Occupational radiation exposure at commercial nuclear power reactors and other facilities, 1993. Volume 15, Twenty-six annual report

International Nuclear Information System (INIS)

Raddatz, C.T.

1995-01-01

This report the occupational radiation exposure information that has been reported to the NRC's Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC licensees during the years 1969 through 1993. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10 CFR 20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC licensed facilities were obtained from reports submitted pursuant to 10 CFR 20.408. The 1993 annual reports submitted by about 360 licensees indicated that approximately 189,711 individuals were monitored, 169,872 of whom were monitored by nuclear power facilities. They incurred an average individual dose of 0.16 rem (cSv) and an average measured dose of about 0.31 (cSv). Termination radiation exposure reports were analyzed to reveal that about 99,749 individuals completed their employment with one or more of the 360 covered licensees during 1993. Some 91,000 of these individuals terminated from power reactor facilities, and about 12,685 of them were considered to be transient workers who received an average dose of 0.49 rem (cSv)

A first-principles approach to total-dose hardness assurance

International Nuclear Information System (INIS)

Fleetwood, D.M.

1995-01-01

A first-principles approach to radiation hardness assurance was described that provides the technical background to the present US and European total-dose radiation hardness assurance test methods for MOS technologies, TM 1019.4 and BS 22900. These test methods could not have been developed otherwise, as their existence depends not on a wealth of empirical comparisons of IC data from ground and space testing, but on a fundamental understanding of MOS defect growth and annealing processes. Rebound testing should become less of a problem for advanced MOS small-signal electronics technologies for systems with total dose requirements below 50--100 krad(SiO 2 ) because of trends toward much thinner gate oxides. For older technologies with thicker gate oxides and for power devices, rebound testing is unavoidable without detailed characterization studies to assess the impact of interface traps on devices response in space. The QML approach is promising for future hardened technologies. A sufficient understanding of process effects on radiation hardness has been developed that should be able to reduce testing costs in the future for hardened parts. Finally, it is hoped that the above discussions have demonstrated that the foundation for cost-effective hardness assurance tests is laid with studies of the basic mechanisms of radiation effects. Without a diligent assessment of new radiation effects mechanisms in future technologies, one cannot be assured that the present generation of radiation test standards will continue to apply

Measurement of TFTR D-T radiation shielding efficiency

International Nuclear Information System (INIS)

Kugel, H.W.; Ascione G.; Elwood, S.

1994-01-01

High power D-T fusion reactor designs presently exhibit complex geometric and material density configurations. Simulations of the radiation shielding required for safe operation and full compliance with all regulatory requirements must include sufficient margin to accommodate uncertainties in material properties and distributions, uncertainties in the final configurations, and uncertainties in approximations employing the homogenization of complex geometries. Measurements of radiation shielding efficiency performed in a realistic D-T tokamak environment can provide empirical guidance for simulating safe, efficient, and cost effective shielding systems for future high power fusion reactors. In this work, the authors present the results of initial measurements of the TFTR radiation shielding efficiency during high power D-T operations with record neutron yields. The TFTR design objective is to limit the total dose-equivalent at the nearest PPPL property lines from all radiation pathways to 10 mrem per calendar year. Compliance with this design objective over a calendar year requires measurements in the presence of typical site backgrounds of about 80 mrem per year