Radiation transport analyses in support of the SNS Target Station Neutron Beam Line Shutters Title I Design

International Nuclear Information System (INIS)

Miller, T.M.; Pevey, R.E.; Lillie, R.A.; Johnson, J.O.

2000-01-01

A detailed radiation transport analysis of the Spallation Neutron Source (SNS) shutters is important for the construction of the SNS because of its impact on conventional facility design, normal operation of the facility, and maintenance operations. Thus far the analysis of the SNS shutter travel gaps has been completed. This analysis was performed using coupled Monte Carlo and multi-dimensional discrete ordinates calculations

Radiation transport: Progress report, July 1, 1987-September 30, 1987

International Nuclear Information System (INIS)

O'Dell, R.D.; Nagy, A.

1988-05-01

Research and development progress in radiation transport for the Los Alamos National Laboratory's Group S-6 for the fourth quarter of FY 87 is reported. Included are unclassified tasks in the areas of Deterministic Radiation Transport, Monte Carlo Radiation Transport, and Cross Sections and Physics. 23 refs., 9 figs

Available computer codes and data for radiation transport analysis

International Nuclear Information System (INIS)

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

1975-01-01

The Radiation Shielding Information Center (RSIC), sponsored and supported by the Energy Research and Development Administration (ERDA) and the Defense Nuclear Agency (DNA), is a technical institute serving the radiation transport and shielding community. It acquires, selects, stores, retrieves, evaluates, analyzes, synthesizes, and disseminates information on shielding and ionizing radiation transport. The major activities include: (1) operating a computer-based information system and answering inquiries on radiation analysis, (2) collecting, checking out, packaging, and distributing large computer codes, and evaluated and processed data libraries. The data packages include multigroup coupled neutron-gamma-ray cross sections and kerma coefficients, other nuclear data, and radiation transport benchmark problem results

Radiative transport-based frequency-domain fluorescence tomography

International Nuclear Information System (INIS)

Joshi, Amit; Rasmussen, John C; Sevick-Muraca, Eva M; Wareing, Todd A; McGhee, John

2008-01-01

We report the development of radiative transport model-based fluorescence optical tomography from frequency-domain boundary measurements. The coupled radiative transport model for describing NIR fluorescence propagation in tissue is solved by a novel software based on the established Attila(TM) particle transport simulation platform. The proposed scheme enables the prediction of fluorescence measurements with non-contact sources and detectors at a minimal computational cost. An adjoint transport solution-based fluorescence tomography algorithm is implemented on dual grids to efficiently assemble the measurement sensitivity Jacobian matrix. Finally, we demonstrate fluorescence tomography on a realistic computational mouse model to locate nM to μM fluorophore concentration distributions in simulated mouse organs

Photonuclear Physics in Radiation Transport - II: Implementation

International Nuclear Information System (INIS)

White, M.C.; Little, R.C.; Chadwick, M.B.; Young, P.G.; MacFarlane, R.E.

2003-01-01

This is the second of two companion papers. The first paper describes model calculations and nuclear data evaluations of photonuclear reactions on isotopes of C, O, Al, Si, Ca, Fe, Cu, Ta, W, and Pb for incident photon energies up to 150 MeV. This paper describes the steps taken to process these files into transport libraries and to update the Monte Carlo N-Particle (MCNP) and MCNPX radiation transport codes to use tabular photonuclear reaction data. The evaluated photonuclear data files are created in the standard evaluated nuclear data file (ENDF) format. These files must be processed by the NJOY data processing system into A Compact ENDF (ACE) files suitable for radiation transport calculations. MCNP and MCNPX have been modified to use these new data in a self-consistent and fully integrated manner. Verification problems were used at each step along the path to check the integrity of the methodology. The resulting methodology and tools provide a comprehensive system for using photonuclear data in radiation transport calculations. Also described are initial validation simulations used to benchmark several of the photonuclear transport tables

Renormalization-group approach to nonlinear radiation-transport problems

International Nuclear Information System (INIS)

Chapline, G.F.

1980-01-01

A Monte Carlo method is derived for solving nonlinear radiation-transport problems that allows one to average over the effects of many photon absorptions and emissions at frequencies where the opacity is large. This method should allow one to treat radiation-transport problems with large optical depths, e.g., line-transport problems, with little increase in computational effort over that which is required for optically thin problems

Statistics of Monte Carlo methods used in radiation transport calculation

International Nuclear Information System (INIS)

Datta, D.

2009-01-01

Radiation transport calculation can be carried out by using either deterministic or statistical methods. Radiation transport calculation based on statistical methods is basic theme of the Monte Carlo methods. The aim of this lecture is to describe the fundamental statistics required to build the foundations of Monte Carlo technique for radiation transport calculation. Lecture note is organized in the following way. Section (1) will describe the introduction of Basic Monte Carlo and its classification towards the respective field. Section (2) will describe the random sampling methods, a key component of Monte Carlo radiation transport calculation, Section (3) will provide the statistical uncertainty of Monte Carlo estimates, Section (4) will describe in brief the importance of variance reduction techniques while sampling particles such as photon, or neutron in the process of radiation transport

Radiation transport. Progress report, April 1-December 31, 1983

International Nuclear Information System (INIS)

O'Dell, R.D.

1984-10-01

Research and development progress in radiation transport by the Los Alamos National Laboratory's Group X-6 for the last nine months of CY 83 is reported. Included are unclassified tasks in the areas of Fission Reactor Neutronics, Deterministic Transport Methods, Monte Carlo Radiation Transport, and Cross Sections and Physics

A multigroup treatment of radiation transport

International Nuclear Information System (INIS)

Tahir, N.A.; Laing, E.W.; Nicholas, D.J.

1980-12-01

A multi-group radiation package is outlined which will accurately handle radiation transfer problems in laser-produced plasmas. Bremsstrahlung, recombination and line radiation are included as well as fast electron Bremsstrahlung radiation. The entire radiation field is divided into a large number of groups (typically 20), which diffuse radiation energy in real space as well as in energy space, the latter occurring via electron-radiation interaction. Using this model a radiation transport code will be developed to be incorporated into MEDUSA. This modified version of MEDUSA will be used to study radiative preheat effects in laser-compression experiments at the Central Laser Facility, Rutherford Laboratory. The model is also relevant to heavy ion fusion studies. (author)

Radiation transport calculation methods in BNCT

International Nuclear Information System (INIS)

Koivunoro, H.; Seppaelae, T.; Savolainen, S.

2000-01-01

Boron neutron capture therapy (BNCT) is used as a radiotherapy for malignant brain tumours. Radiation dose distribution is necessary to determine individually for each patient. Radiation transport and dose distribution calculations in BNCT are more complicated than in conventional radiotherapy. Total dose in BNCT consists of several different dose components. The most important dose component for tumour control is therapeutic boron dose D B . The other dose components are gamma dose D g , incident fast neutron dose D f ast n and nitrogen dose D N . Total dose is a weighted sum of the dose components. Calculation of neutron and photon flux is a complex problem and requires numerical methods, i.e. deterministic or stochastic simulation methods. Deterministic methods are based on the numerical solution of Boltzmann transport equation. Such are discrete ordinates (SN) and spherical harmonics (PN) methods. The stochastic simulation method for calculation of radiation transport is known as Monte Carlo method. In the deterministic methods the spatial geometry is partitioned into mesh elements. In SN method angular integrals of the transport equation are replaced with weighted sums over a set of discrete angular directions. Flux is calculated iteratively for all these mesh elements and for each discrete direction. Discrete ordinates transport codes used in the dosimetric calculations are ANISN, DORT and TORT. In PN method a Legendre expansion for angular flux is used instead of discrete direction fluxes, land the angular dependency comes a property of vector function space itself. Thus, only spatial iterations are required for resulting equations. A novel radiation transport code based on PN method and tree-multigrid technique (TMG) has been developed at VTT (Technical Research Centre of Finland). Monte Carlo method solves the radiation transport by randomly selecting neutrons and photons from a prespecified boundary source and following the histories of selected particles

Transport and attenuation of radiations

CERN Document Server

Nimal, J C

2003-01-01

This article treats of the calculation methods used for the dimensioning of the protections against radiations. The method consists in determining for a given point the flux of particles coming from a source at a given time. A strong attenuation (of about some few mu Sv.h sup - sup 1) is in general expected between the source and the areas accessible to the personnel or the public. The calculation has to take into account a huge number of radiation-matter interactions and to solve the integral-differential transport equation which links the particles flux to the source. Several methods exist from the simplified physical model with numerical developments to the more or less precise resolution of the transport equation. These methods allows also the calculation of the uncertainties of equivalent dose rates, heat sources, structure damages using the data covariances (efficient cross-sections, modeling, etc..): 1 - transport equation; 2 - Monte-Carlo method; 3 - semi-numerical methods S sub N; 4 - methods based o...

Radiological emergency: road map for radiation accident victim transport

International Nuclear Information System (INIS)

Costa, V.S.G.; Alcantara, Y.P.; Lima, C.M.A.; Silva, F. C. A. da

2017-01-01

During a radiological or nuclear emergency, a number of necessary actions are taken, both within the radiation protection of individuals and the environment, involving many institutions and highly specialized personnel. Among them it is possible to emphasize the air transportation of radiation accident victims.The procedures and measures for the safe transport of these radiation accident victims are generally the responsibility of the armed forces, specifically the Aeronautics, with the action denominated 'Aeromedical Military Evacuation of Radiation Accident Victims'. The experience with the Radiological Accident of Goiânia demonstrated the importance of adequate preparation and response during a radiological emergency and the need for procedures and measures with regard to the transport of radiation victims are clearly defined and clearly presented for the effectiveness of the actions. This work presents the necessary actions for the transport of radiation accident victim during a radiological emergency, through the road map technique, which has been widely used in scientific technical area to facilitate understanding and show the way to be followed to reach the proposed objectives

Analysis of transport of collimated radiation in a participating media using the lattice Boltzmann method

International Nuclear Information System (INIS)

Mishra, Subhash C.; Vernekar, Rohan Ranganath

2012-01-01

Application of the lattice Boltzmann method (LBM) recently proposed by Asinari et al. [Asinari P, Mishra SC, Borchiellini R. A lattice Boltzmann formulation to the analysis of radiative heat transfer problems in a participating medium. Numer Heat Transfer B 2010; 57:126–146] is extended to the analysis of transport of collimated radiation in a planar participating medium. To deal with azimuthally symmetric radiation in planar medium, a new lattice structure for the LBM is used. The transport of the collimated component in the medium is analysed by two different, viz., flux splitting and direct approaches. For different angles of incidence of the collimated radiation, the LBM formulation is tested for the effects of the extinction coefficient, the anisotropy factor, and the boundary emissivities on heat flux and emissive power distributions. Results are compared with the benchmark results obtained using the finite volume method. Both the approaches in LBM provide accurate results. -- Highlights: ► Transport of collimated radiation in participating media is studied. ► Usage of Lattice Boltzmann method (LBM) is extended in this study. ► In LBM, flux splitting and direct approaches are proposed. ► Effects of various parameters are studied on heat flux and temperature profiles. ► In all cases, LBM provides correct results.

On the derivation of vector radiative transfer equation for polarized radiative transport in graded index media

International Nuclear Information System (INIS)

Zhao, J.M.; Tan, J.Y.; Liu, L.H.

2012-01-01

Light transport in graded index media follows a curved trajectory determined by Fermat's principle. Besides the effect of variation of the refractive index on the transport of radiative intensity, the curved ray trajectory will induce geometrical effects on the transport of polarization ellipse. This paper presents a complete derivation of vector radiative transfer equation for polarized radiation transport in absorption, emission and scattering graded index media. The derivation is based on the analysis of the conserved quantities for polarized light transport along curved trajectory and a novel approach. The obtained transfer equation can be considered as a generalization of the classic vector radiative transfer equation that is only valid for uniform refractive index media. Several variant forms of the transport equation are also presented, which include the form for Stokes parameters defined with a fixed reference and the Eulerian forms in the ray coordinate and in several common orthogonal coordinate systems.

Radiation protection programmes for the transport of radioactive material. Safety guide

International Nuclear Information System (INIS)

2007-01-01

This Safety Guide provides guidance on meeting the requirements for the establishment of radiation protection programmes (RPPs) for the transport of radioactive material, to optimize radiation protection in order to meet the requirements for radiation protection that underlie the Regulations for the Safe Transport of Radioactive Material. This Guide covers general aspects of meeting the requirements for radiation protection, but does not cover criticality safety or other possible hazardous properties of radioactive material. The annexes of this Guide include examples of RPPs, relevant excerpts from the Transport Regulations, examples of total dose per transport index handled, a checklist for road transport, specific segregation distances and emergency instructions for vehicle operators

ipole: Semianalytic scheme for relativistic polarized radiative transport

Science.gov (United States)

Moscibrodzka, Monika; Gammie, Charles F.

2018-04-01

ipole is a ray-tracing code for covariant, polarized radiative transport particularly useful for modeling Event Horizon Telescope sources, though may also be used for other relativistic transport problems. The code extends the ibothros scheme for covariant, unpolarized transport using two representations of the polarized radiation field: in the coordinate frame, it parallel transports the coherency tensor, and in the frame of the plasma, it evolves the Stokes parameters under emission, absorption, and Faraday conversion. The transport step is as spacetime- and coordinate- independent as possible; the emission, absorption, and Faraday conversion step is implemented using an analytic solution to the polarized transport equation with constant coefficients. As a result, ipole is stable, efficient, and produces a physically reasonable solution even for a step with high optical depth and Faraday depth.

Transport of radioactivity and radiation

International Nuclear Information System (INIS)

De Beer, G.P.

1988-01-01

The movement of radioactivity and radiation is of prime importance in a wide variety of fields and the present advanced degree of knowledge of transport mechanisms is due largely to the application of sophisticated computer techniques

DIAPHANE: A portable radiation transport library for astrophysical applications

Science.gov (United States)

Reed, Darren S.; Dykes, Tim; Cabezón, Rubén; Gheller, Claudio; Mayer, Lucio

2018-05-01

One of the most computationally demanding aspects of the hydrodynamical modelingof Astrophysical phenomena is the transport of energy by radiation or relativistic particles. Physical processes involving energy transport are ubiquitous and of capital importance in many scenarios ranging from planet formation to cosmic structure evolution, including explosive events like core collapse supernova or gamma-ray bursts. Moreover, the ability to model and hence understand these processes has often been limited by the approximations and incompleteness in the treatment of radiation and relativistic particles. The DIAPHANE project has focused on developing a portable and scalable library that handles the transport of radiation and particles (in particular neutrinos) independently of the underlying hydrodynamic code. In this work, we present the computational framework and the functionalities of the first version of the DIAPHANE library, which has been successfully ported to three different smoothed-particle hydrodynamic codes, GADGET2, GASOLINE and SPHYNX. We also present validation of different modules solving the equations of radiation and neutrino transport using different numerical schemes.

Los Alamos radiation transport code system on desktop computing platforms

International Nuclear Information System (INIS)

Briesmeister, J.F.; Brinkley, F.W.; Clark, B.A.; West, J.T.

1990-01-01

The Los Alamos Radiation Transport Code System (LARTCS) consists of state-of-the-art Monte Carlo and discrete ordinates transport codes and data libraries. These codes were originally developed many years ago and have undergone continual improvement. With a large initial effort and continued vigilance, the codes are easily portable from one type of hardware to another. The performance of scientific work-stations (SWS) has evolved to the point that such platforms can be used routinely to perform sophisticated radiation transport calculations. As the personal computer (PC) performance approaches that of the SWS, the hardware options for desk-top radiation transport calculations expands considerably. The current status of the radiation transport codes within the LARTCS is described: MCNP, SABRINA, LAHET, ONEDANT, TWODANT, TWOHEX, and ONELD. Specifically, the authors discuss hardware systems on which the codes run and present code performance comparisons for various machines

Parallel thermal radiation transport in two dimensions

International Nuclear Information System (INIS)

Smedley-Stevenson, R.P.; Ball, S.R.

2003-01-01

This paper describes the distributed memory parallel implementation of a deterministic thermal radiation transport algorithm in a 2-dimensional ALE hydrodynamics code. The parallel algorithm consists of a variety of components which are combined in order to produce a state of the art computational capability, capable of solving large thermal radiation transport problems using Blue-Oak, the 3 Tera-Flop MPP (massive parallel processors) computing facility at AWE (United Kingdom). Particular aspects of the parallel algorithm are described together with examples of the performance on some challenging applications. (author)

Parallel thermal radiation transport in two dimensions

Energy Technology Data Exchange (ETDEWEB)

Smedley-Stevenson, R.P.; Ball, S.R. [AWE Aldermaston (United Kingdom)

2003-07-01

This paper describes the distributed memory parallel implementation of a deterministic thermal radiation transport algorithm in a 2-dimensional ALE hydrodynamics code. The parallel algorithm consists of a variety of components which are combined in order to produce a state of the art computational capability, capable of solving large thermal radiation transport problems using Blue-Oak, the 3 Tera-Flop MPP (massive parallel processors) computing facility at AWE (United Kingdom). Particular aspects of the parallel algorithm are described together with examples of the performance on some challenging applications. (author)

Radiation Exposure Analyses Supporting the Development of Solar Particle Event Shielding Technologies

Science.gov (United States)

Walker, Steven A.; Clowdsley, Martha S.; Abston, H. Lee; Simon, Hatthew A.; Gallegos, Adam M.

2013-01-01

NASA has plans for long duration missions beyond low Earth orbit (LEO). Outside of LEO, large solar particle events (SPEs), which occur sporadically, can deliver a very large dose in a short amount of time. The relatively low proton energies make SPE shielding practical, and the possibility of the occurrence of a large event drives the need for SPE shielding for all deep space missions. The Advanced Exploration Systems (AES) RadWorks Storm Shelter Team was charged with developing minimal mass SPE storm shelter concepts for missions beyond LEO. The concepts developed included "wearable" shields, shelters that could be deployed at the onset of an event, and augmentations to the crew quarters. The radiation transport codes, human body models, and vehicle geometry tools contained in the On-Line Tool for the Assessment of Radiation In Space (OLTARIS) were used to evaluate the protection provided by each concept within a realistic space habitat and provide the concept designers with shield thickness requirements. Several different SPE models were utilized to examine the dependence of the shield requirements on the event spectrum. This paper describes the radiation analysis methods and the results of these analyses for several of the shielding concepts.

Radiation inactivation studies of renal brush border water and urea transport

International Nuclear Information System (INIS)

Verkman, A.S.; Dix, J.A.; Seifter, J.L.; Skorecki, K.L.; Jung, C.Y.; Ausiello, D.A.

1985-01-01

Radiation inactivation was used to determine the nature and molecular weight of water and urea transport pathways in brush border membrane vesicles (BBMV) isolated from rabbit renal cortex. BBMV were frozen to -50 degrees C, irradiated with 1.5 MeV electrons, thawed, and assayed for transport or enzyme activity. The freezing process had no effect on enzyme or transport kinetics. BBMV alkaline phosphatase activity gave linear ln(activity) vs. radiation dose plots with a target size of 68 +/- 3 kDa, similar to previously reported values. Water and solute transport were measured using the stopped-flow light-scattering technique. The rates of acetamide and osmotic water transport did not depend on radiation dose (0-7 Mrad), suggesting that transport of these substances does not require a protein carrier. In contrast, urea and thiourea transport gave linear ln(activity) vs. dose curves with a target size of 125-150 kDa; 400 mM urea inhibited thiourea flux by -50% at 0 and 4.7 Mrad, showing that radiation does not affect inhibitor binding to surviving transporters. These studies suggest that BBMV urea transport requires a membrane protein, whereas osmotic water transport does not

Multi-Dimensional Radiation Transport in Dense Z-pinch Wire Array Plasmas

Science.gov (United States)

Jennings, C. A.; Chittenden, J. P.; Ciardi, A.; Sherlock, M.; Lebedev, S. V.

2004-11-01

Z-pinch wire arrays have proven to be an extremely efficient high yield, short pulse x-ray source with potential application to ICF. The characteristics of the x-ray pulse produced have been shown to be largely determined by non-uniform break up of the wires leading to a highly irregular distribution of mass which implodes towards the axis. Modelling the inherent 3D nature of these plasmas is already computationally very expensive, and so energy exchange through radiation is frequently neglected, assuming instead an optically thin radiation loss model. With a significant fraction of the total energy at late stages being radiated through a dense, optically thick plasma this approach is potentially inadequate in fully describing the implosion. We analyse the effects of radiative cooling and radiation transport on stagnation and precursor development in wire array z-pinch implosions. A three temperature multidimensional MHD code using a single group radiation diffusion model is used to study radiation trapping in the precursor, and the effects of preheating on the implosion dynamics. Energy exchange in the final stagnated plasma and its effects on the x-ray pulse shape is also discussed. This work was partially supported by the SSAA program of the NNSA through DoE cooperative agreement DE-F03-02NA00057.

Two-dimensional radiation shielding optimization analysis of spent fuel transport container

International Nuclear Information System (INIS)

Tian Yingnan; Chen Yixue; Yang Shouhai

2013-01-01

The intelligent radiation shielding optimization design software platform is a one-dimensional multi-target radiation shielding optimization program which is developed on the basis of the genetic algorithm program and one-dimensional discrete ordinate program-ANISN. This program was applied in the optimization design analysis of the spent fuel transport container radiation shielding. The multi-objective optimization calculation model of the spent fuel transport container radiation shielding was established, and the optimization calculation of the spent fuel transport container weight and radiation dose rate was carried by this program. The calculation results were checked by Monte-Carlo program-MCNP/4C. The results show that the weight of the optimized spent fuel transport container decreases to 81.1% of the origin and the radiation dose rate decreases to below 65.4% of the origin. The maximum deviation between the calculated values from the program and the MCNP is below 5%. The results show that the optimization design scheme is feasible and the calculation result is correct. (authors)

Study of Radiation Shielding Analysis for Low-Intermediate Level Waste Transport Ship

Energy Technology Data Exchange (ETDEWEB)

Kim, Dohyung; Lee, Unjang; Song, Yangsoo; Kim, Sukhoon; Ko, Jaehoon [Korea Nuclear Engineering and Service Corporation, Seoul (Korea, Republic of)

2007-07-01

In Korea, it is planed to transport Low-Intermediate Level Radioactive Waste (LILW) from each nuclear power plant site to Kyongju LILW repository after 2009. Transport through the sea using ship is one of the most prospective ways of LILW transport for current situation in Korea. There are domestic and international regulations for radiation dose limit for radioactive material transport. In this article, radiation shielding analysis for LILW transport ship is performed using 3-D computer simulation code, MCNP. As a result, the thickness and materials for radiation shielding walls next to cargo in the LILW transport ship are determined.

Environmental analyses of land transportation systems in The Netherlands

NARCIS (Netherlands)

Bouwman, Mirjan E.; Moll, Henri C.

Environmental analyses of the impact of transportation systems on the environment from the cradle to the grave are rare. This article makes a comparison of various Dutch passenger transportation systems by studying their complete life-cycle energy use. Moreover, systems are compared according to

Radiation safety in sea transport of radioactive material in Japan

International Nuclear Information System (INIS)

Odano, N.; Yanagi, H.

2004-01-01

Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured

Radiation safety in sea transport of radioactive material in Japan

Energy Technology Data Exchange (ETDEWEB)

Odano, N. [National Maritime Research Inst., Tokyo (Japan); Yanagi, H. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan)

2004-07-01

Radiation safety for sea transport of radioactive material in Japan has been discussed based on records of the exposed dose of sea transport workers and measured data of dose rate equivalents distribution inboard exclusive radioactive material shipping vessels. Recent surveyed records of the exposed doses of workers who engaged in sea transport operation indicate that exposed doses of transport workers are significantly low. Measured distribution of the exposed dose equivalents inboard those vessels indicates that dose rate equivalents inside those vessels are lower than levels regulated by the transport regulations of Japan. These facts clarify that radiation safety of inboard environment and handling of transport casks in sea transport of radioactive material in Japan are assured.

Use of implicit Monte Carlo radiation transport with hydrodynamics and compton scattering

International Nuclear Information System (INIS)

Fleck, J.A. Jr.

1971-03-01

It is shown that the combination of implicit radiation transport and hydrodynamics, Compton scattering, and any other energy transport can be simply carried out by a ''splitting'' procedure. Contributions to material energy exchange can be reckoned separately for hydrodynamics, radiation transport without scattering, Compton scattering, plus any other possible energy exchange mechanism. The radiation transport phase of the calculation would be implicit, but the hydrodynamics and Compton portions would not, leading to possible time step controls. The time step restrictions which occur on radiation transfer due to large Planck mean absorption cross-sections would not occur

Sandia Transportation Technical Environmental Information Center and its application to transportation risk analyses

International Nuclear Information System (INIS)

Foley, J.T.; Davidson, C.A.; McClure, J.D.

1978-01-01

Purpose of this paper is to describe an applied research activity which is fundamental to the conduct of transportation analyses: the collection, analysis, storage, and retrieval of information on the intensities of technical environments. This paper describes the collection system which provides such a service to official researchers in transportation analysis and the applications of this information in the area of risk analysis

Academic Training - The use of Monte Carlo radiation transport codes in radiation physics and dosimetry

CERN Multimedia

Françoise Benz

2006-01-01

2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 27, 28, 29 June 11:00-12:00 - TH Conference Room, bldg. 4 The use of Monte Carlo radiation transport codes in radiation physics and dosimetry F. Salvat Gavalda,Univ. de Barcelona, A. FERRARI, CERN-AB, M. SILARI, CERN-SC Lecture 1. Transport and interaction of electromagnetic radiation F. Salvat Gavalda,Univ. de Barcelona Interaction models and simulation schemes implemented in modern Monte Carlo codes for the simulation of coupled electron-photon transport will be briefly reviewed. Different schemes for simulating electron transport will be discussed. Condensed algorithms, which rely on multiple-scattering theories, are comparatively fast, but less accurate than mixed algorithms, in which hard interactions (with energy loss or angular deflection larger than certain cut-off values) are simulated individually. The reliability, and limitations, of electron-interaction models and multiple-scattering theories will be analyzed. Benchmark comparisons of simu...

Intense radiative heat transport across a nano-scale gap

International Nuclear Information System (INIS)

Budaev, Bair V.; Ghafari, Amin; Bogy, David B.

2016-01-01

In this paper, we analyze the radiative heat transport in layered structures. The analysis is based on our prior description of the spectrum of thermally excited waves in systems with a heat flux. The developed method correctly predicts results for all known special cases for both large and closing gaps. Numerical examples demonstrate the applicability of our approach to the calculation of the radiative heat transport coefficient across various layered structures.

Radiation physics and shielding codes and analyses applied to design-assist and safety analyses of CANDUR and ACRTM reactors

International Nuclear Information System (INIS)

Aydogdu, K.; Boss, C. R.

2006-01-01

This paper discusses the radiation physics and shielding codes and analyses applied in the design of CANDU and ACR reactors. The focus is on the types of analyses undertaken rather than the inputs supplied to the engineering disciplines. Nevertheless, the discussion does show how these analyses contribute to the engineering design. Analyses in radiation physics and shielding can be categorized as either design-assist or safety and licensing (accident) analyses. Many of the analyses undertaken are designated 'design-assist' where the analyses are used to generate recommendations that directly influence plant design. These recommendations are directed at mitigating or reducing the radiation hazard of the nuclear power plant with engineered systems and components. Thus the analyses serve a primary safety function by ensuring the plant can be operated with acceptable radiation hazards to the workers and public. In addition to this role of design assist, radiation physics and shielding codes are also deployed in safety and licensing assessments of the consequences of radioactive releases of gaseous and liquid effluents during normal operation and gaseous effluents following accidents. In the latter category, the final consequences of accident sequences, expressed in terms of radiation dose to members of the public, and inputs to accident analysis, e.g., decay heat in fuel following a loss-of-coolant accident, are also calculated. Another role of the analyses is to demonstrate that the design of the plant satisfies the principle of ALARA (as low as reasonably achievable) radiation doses. This principle is applied throughout the design process to minimize worker and public doses. The principle of ALARA is an inherent part of all design-assist recommendations and safety and licensing assessments. The main focus of an ALARA exercise at the design stage is to minimize the radiation hazards at the source. This exploits material selection and impurity specifications and relies

LDRD Final Review: Radiation Transport Calculations

Energy Technology Data Exchange (ETDEWEB)

Goorley, John Timothy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morgan, George Lake [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lestone, John Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-06-22

Both high-fidelity & toy simulations are being used to understand measured signals and improve the Area 11 NDSE diagnostic. We continue to gain more and more confidence in the ability for MCNP to simulate neutron and photon transport from source to radiation detector.

Radiation doses from the transport of radioactive materials

International Nuclear Information System (INIS)

Shaw, K.B.; Holyoak, B.

1983-01-01

A summary is given of a study on radiation exposure resulting from the transport of radioactive materials within the United Kingdom. It was concluded that the transport of technetium generators for hospital use accounts for about 49% of the occupational exposure for the normal transport of radioactive materials. Other isotopes for medical and industrial use contribute about 38% of the occupational exposure and the remainder can be attributed to transportation as a result of the nuclear fuel cycle including the transport of irradiated nuclear fuel. The occupational collective dose for all modes of transport is estimated at 1 man Sv y -1 . (UK)

IPOLE - semi-analytic scheme for relativistic polarized radiative transport

Science.gov (United States)

Mościbrodzka, M.; Gammie, C. F.

2018-03-01

We describe IPOLE, a new public ray-tracing code for covariant, polarized radiative transport. The code extends the IBOTHROS scheme for covariant, unpolarized transport using two representations of the polarized radiation field: In the coordinate frame, it parallel transports the coherency tensor; in the frame of the plasma it evolves the Stokes parameters under emission, absorption, and Faraday conversion. The transport step is implemented to be as spacetime- and coordinate- independent as possible. The emission, absorption, and Faraday conversion step is implemented using an analytic solution to the polarized transport equation with constant coefficients. As a result, IPOLE is stable, efficient, and produces a physically reasonable solution even for a step with high optical depth and Faraday depth. We show that the code matches analytic results in flat space, and that it produces results that converge to those produced by Dexter's GRTRANS polarized transport code on a complicated model problem. We expect IPOLE will mainly find applications in modelling Event Horizon Telescope sources, but it may also be useful in other relativistic transport problems such as modelling for the IXPE mission.

Spent fuel shipping costs for transportation logistics analyses

International Nuclear Information System (INIS)

Cole, B.M.; Cross, R.E.; Cashwell, J.W.

1983-05-01

Logistics analyses supplied to the nuclear waste management programs of the U.S. Department of Energy through the Transportation Technology Center (TTC) at Sandia National Laboratories are used to predict nuclear waste material logistics, transportation packaging demands, shipping and receiving rates and transportation-related costs for alternative strategies. This study is an in-depth analysis of the problems and contingencies associated with the costs of shipping irradiated reactor fuel. These costs are extremely variable however, and have changed frequently (sometimes monthly) during the past few years due to changes in capital, fuel, and labor costs. All costs and charges reported in this study are based on January 1982 data using existing transport cask systems and should be used as relative indices only. Actual shipping costs would be negotiable for each origin-destination combination

Induced Compton-scattering effects in radiation-transport approximations

International Nuclear Information System (INIS)

Gibson, D.R. Jr.

1982-02-01

The method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

Experimental validation of GADRAS's coupled neutron-photon inverse radiation transport solver

International Nuclear Information System (INIS)

Mattingly, John K.; Mitchell, Dean James; Harding, Lee T.

2010-01-01

Sandia National Laboratories has developed an inverse radiation transport solver that applies nonlinear regression to coupled neutron-photon deterministic transport models. The inverse solver uses nonlinear regression to fit a radiation transport model to gamma spectrometry and neutron multiplicity counting measurements. The subject of this paper is the experimental validation of that solver. This paper describes a series of experiments conducted with a 4.5 kg sphere of α-phase, weapons-grade plutonium. The source was measured bare and reflected by high-density polyethylene (HDPE) spherical shells with total thicknesses between 1.27 and 15.24 cm. Neutron and photon emissions from the source were measured using three instruments: a gross neutron counter, a portable neutron multiplicity counter, and a high-resolution gamma spectrometer. These measurements were used as input to the inverse radiation transport solver to evaluate the solver's ability to correctly infer the configuration of the source from its measured radiation signatures.

Dispersive effects in radiation transport and radiation hydrodynamics in matter at high density

International Nuclear Information System (INIS)

Crowley, B.J.B.

1983-01-01

In a recent research program (reported in AWRE 0 20/82) I have investigated the generalisation of the equations of radiation hydrodynamics when electromagnetic radiation is assumed to obey a linear-response dispersion relation of the form nω=kc where the refractive index n depends on the frequency ω and/or wave number k. From the application of the Boltzmann-Liouville transport theory to photons in the short-wavelength (geometrical optics) limit, I derive the energy and momentum equations which, when combined with a classical (Euler-Lagrange-Navier-Stokes) treatment of a fluid material medium in LTE, yield a complete dynamical theory of linear interactions (+ stimulated processes) between incoherent (thermal) radiation and dense, locally isotropic matter. The theory includes an account of pondero-motive forces and electro (magneto) striction. Moreover, it is apparently capable of being generalised to non-linear interactions in which the refractive index depends on the local specific intensity of the radiation field, and, to some extent, to the treatment of high-frequency coherent radiation. The generalisation of various approximated forms of radiation-transport theory (esp. diffusion) has been considered in detail. Some problems remain however. One such is the treatment of anomalous dispersion. Current research work is concentrating on the interesting atomic physics aspects of electromagnetic (esp. radiative) properties of a dispersive material medium

Transport methods: general. 1. The Analytical Monte Carlo Method for Radiation Transport Calculations

International Nuclear Information System (INIS)

Martin, William R.; Brown, Forrest B.

2001-01-01

We present an alternative Monte Carlo method for solving the coupled equations of radiation transport and material energy. This method is based on incorporating the analytical solution to the material energy equation directly into the Monte Carlo simulation for the radiation intensity. This method, which we call the Analytical Monte Carlo (AMC) method, differs from the well known Implicit Monte Carlo (IMC) method of Fleck and Cummings because there is no discretization of the material energy equation since it is solved as a by-product of the Monte Carlo simulation of the transport equation. Our method also differs from the method recently proposed by Ahrens and Larsen since they use Monte Carlo to solve both equations, while we are solving only the radiation transport equation with Monte Carlo, albeit with effective sources and cross sections to represent the emission sources. Our method bears some similarity to a method developed and implemented by Carter and Forest nearly three decades ago, but there are substantive differences. We have implemented our method in a simple zero-dimensional Monte Carlo code to test the feasibility of the method, and the preliminary results are very promising, justifying further extension to more realistic geometries. (authors)

Department of Environmental and Radiation Transport Physics - Overview

International Nuclear Information System (INIS)

Woznicka, U.

2001-01-01

Full text: We deal with environmental physics and the radiation transport physics, both theoretically and experimentally. Some results find their way to practical applications. Our environmental physics research encompasses hydrogeological problems as well as measurements of trace elements in the atmosphere and in the water. Theoretical (analytical and numerical) and experimental issues of the radiation transport and radiation fields are our main field of research. The interest in radiation transport phenomena is stimulated by their importance for the environmental physics, industrial and nuclear facilities and methods of geophysical. Environmental isotopes and noble gases are used in the investigation of water-bearing geological formations in order to determine the origin and age of groundwater. The papers listed below and three ''Reports on research'' present recent achievements in this field. The gas chromatography methods are used for monitoring the anthropogenic trace gases (SF 6 and freons), which participate in the Earth green-house effect. A very high detection level of SF 6 in water, 0.0028 fg/cm 3 H 2 0, has been reached as required for hydrogeological purposes. A preliminary verification of the SF 6 tracer method for dating young groundwaters by the tritium method has been carried out. We carried on the work on a method of radon measurement in soil in connection with geological conditions. The national seminar ''Radon in Environment'' organized at the INP aroused an interest of Polish scientific centres in that field. The seminar gathered 60 participants who presented 24 oral reports and 8 posters. Within the scope of the radiation transport physics we studied thermal neutron transport in finite hydrogenous media. Advantages and limitations of a Monte Carlo code (MCNP) in thermal neutron transport simulations have been examined by both the analytical solution and the experiment on the INP pulsed neutron generator. An interesting contribution to the

Radiation transport in MEDUSA

International Nuclear Information System (INIS)

Rose, S.J.; Evans, R.G.

1983-09-01

The transport of energy by X-ray photons has been included in the lD Lagrangian hydrodynamics code, MEDUSA. Calculations of the implosion by 0.53 μm laser irradiation of plastic and glass microballoons of current interest at the Central Laser Facility show that radiation preheats the fill gas and alters the temperature and density profiles during the implosion. A lower maximum gas temperature is obtained and this results, for a DT gas fill, in a greatly reduced neutron yield. (author)

MCNP benchmark analyses of critical experiments for the Space Nuclear Thermal Propulsion program

International Nuclear Information System (INIS)

Selcow, E.C.; Cerbone, R.J.; Ludewig, H.; Mughabghab, S.F.; Schmidt, E.; Todosow, M.; Parma, E.J.; Ball, R.M.; Hoovler, G.S.

1993-01-01

Benchmark analyses have been performed of Particle Bed Reactor (PBR) critical experiments (CX) using the MCNP radiation transport code. The experiments have been conducted at the Sandia National Laboratory reactor facility in support of the Space Nuclear Thermal Propulsion (SNTP) program. The test reactor is a nineteen element water moderated and reflected thermal system. A series of integral experiments have been carried out to test the capabilities of the radiation transport codes to predict the performance of PBR systems. MCNP was selected as the preferred radiation analysis tool for the benchmark experiments. Comparison between experimental and calculational results indicate close agreement. This paper describes the analyses of benchmark experiments designed to quantify the accuracy of the MCNP radiation transport code for predicting the performance characteristics of PBR reactors

MCNP benchmark analyses of critical experiments for the Space Nuclear Thermal Propulsion program

Science.gov (United States)

Selcow, Elizabeth C.; Cerbone, Ralph J.; Ludewig, Hans; Mughabghab, Said F.; Schmidt, Eldon; Todosow, Michael; Parma, Edward J.; Ball, Russell M.; Hoovler, Gary S.

1993-01-01

Benchmark analyses have been performed of Particle Bed Reactor (PBR) critical experiments (CX) using the MCNP radiation transport code. The experiments have been conducted at the Sandia National Laboratory reactor facility in support of the Space Nuclear Thermal Propulsion (SNTP) program. The test reactor is a nineteen element water moderated and reflected thermal system. A series of integral experiments have been carried out to test the capabilities of the radiation transport codes to predict the performance of PBR systems. MCNP was selected as the preferred radiation analysis tool for the benchmark experiments. Comparison between experimental and calculational results indicate close agreement. This paper describes the analyses of benchmark experiments designed to quantify the accuracy of the MCNP radiation transport code for predicting the performance characteristics of PBR reactors.

Radiation field analyses in reactor vessels of PWRs

Energy Technology Data Exchange (ETDEWEB)

Fukuya, Koji; Nakata, Hayato; Fujii, Katsuhiko; Kimura, Itsuro [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan); Ohmura, Masaki; Kitagawa, Hideo [Mitsubishi Heavy Industries, Ltd., Nuclear Energy Systems Engineering Center, Yokohama, Kanagawa (Japan); Itoh, Taku; Shin, Kazuo [Kyoto Univ. (Japan). Faculty of Engineering

2002-09-01

Radiation analysis in reactor vessels of PWRs were performed using three calculation codes (two dimensional transport code DORT, three dimensional transport code TORT and three dimensional Monte Carlo code MCNP) and three cross section data (ENDF/B-IV, ENDF/B-VI and JENDL3.2) to improve accuracy of estimation for neutron flux, gamma-ray flux and displacement per atom (dpa). The calculations using DORT at a surveillance position agreed with the dosimetry measurements for the three cross sections. The calculated neutron spectra using the three cross sections at the reactor vessels and the surveillance position were quite similar to each other. The difference in the cross sections gave small impacts on the fluence estimation. The ratio of the calculations to the measurements using TORT was similar to those using DORT, indicating that TORT is applicable to the radiation analysis in PWRs. The MCNP calculations resulted in a similar agreement with the dosimeter measurement to the DORT calculation while they needed a long computing time. Improvement of calculation techniques is needed for application of MCNP. The calculated dpa agreed within 10% for the three cross sections. (author)

Induced Compton scattering effects in radiation transport approximations

International Nuclear Information System (INIS)

Gibson, D.R. Jr.

1982-01-01

In this thesis the method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

Overview. Department of Environmental and Radiation Transport Physics. Section 6

Energy Technology Data Exchange (ETDEWEB)

Loskiewicz, J. [Institute of Nuclear Physics, Cracow (Poland)

1995-12-31

Research activities in the Department of Environmental and Radiation Transport Physics are carried out by three Laboratories: Laboratory of Environmental Physics, Laboratory of Neutron Transport Physics and Laboratory of Physics and Modeling of Radiation Transport. The researches provided in 1994 cover: tracer transport and flows in porous media, studies on pollution in atmospheric air, physics of molecular phenomena in chromatographic detectors, studies on neutron transport in heterogenous media, studies on evaluation of neutron cross-section in the thermal region, studies on theory and utilization of neural network in data evaluation, numerical modelling of particle cascades for particle accelerator shielding purpose. In this section the description of mentioned activities as well as the information about personnel employed in the Department, papers and reports published in 1994, contribution to conferences and grants is also given.

Overview. Department of Environmental and Radiation Transport Physics. Section 6

Energy Technology Data Exchange (ETDEWEB)

Loskiewicz, J [Institute of Nuclear Physics, Cracow (Poland)

1996-12-31

Research activities in the Department of Environmental and Radiation Transport Physics are carried out by three Laboratories: Laboratory of Environmental Physics, Laboratory of Neutron Transport Physics and Laboratory of Physics and Modeling of Radiation Transport. The researches provided in 1994 cover: tracer transport and flows in porous media, studies on pollution in atmospheric air, physics of molecular phenomena in chromatographic detectors, studies on neutron transport in heterogenous media, studies on evaluation of neutron cross-section in the thermal region, studies on theory and utilization of neural network in data evaluation, numerical modelling of particle cascades for particle accelerator shielding purpose. In this section the description of mentioned activities as well as the information about personnel employed in the Department, papers and reports published in 1994, contribution to conferences and grants is also given.

Survey of radiation protection programmes for transport; Etude des programmes de radioprotection pour les transports de matieres radioactives

Energy Technology Data Exchange (ETDEWEB)

Lizot, M.T.; Perrin, M.L.; Sert, G. [CEA Fontenay-aux-Roses, Inst. de Protection et de Surete Nucleaire, Dept. de Protection et de Surete Nucleaire, 92 (France); Lange, F.; Schwarz, G.; Feet, H.J.; Christ, R. [Gesellschaft fur Anlagen-und Reaktorsicherheit, GRS, mbH, Cologne (Germany); Shaw, K.B.; Hughes, J.S.; Gelder, R. [National Radiological Protection Board (NRPB), Oxon, OX (United Kingdom)

2001-07-01

The survey of radiation protection programmes for transport has been jointly performed by three scientific organisations I.P.S.N. (France), G.R.S. ( Germany), and N.R.P.B. (United kingdom) on behalf of the European Commission and the pertaining documentation summarises the findings and conclusions of the work that was undertaken with the principal objectives to provide guidance on the establishment, implementation and application of radiation protection programmes for the transport of radioactive materials by operators and the assessment and evaluation of such programmes by the competent authority and to review currently existing radiation protection programmes for the transport of radioactive materials. (N.C.)

Some factors affecting radiative heat transport in PWR cores

International Nuclear Information System (INIS)

Hall, A.N.

1989-04-01

This report discusses radiative heat transport in Pressurized Water Reactor cores, using simple models to illustrate basic features of the transport process. Heat transport by conduction and convection is ignored in order to focus attention on the restrictions on radiative heat transport imposed by the geometry of the heat emitting and absorbing structures. The importance of the spacing of the emitting and absorbing structures is emphasised. Steady state temperature distributions are found for models of cores which are uniformly heated by fission product decay. In all of the models, a steady state temperature distribution can only be obtained if the central core temperature is in excess of the melting point of UO 2 . It has recently been reported that the MIMAS computer code, which takes into account radiative heat transport, has been used to model the heat-up of the Three Mile Island-2 reactor core, and the computations indicate that the core could not have reached the melting point of UO 2 at any time or any place. We discuss this result in the light of the calculations presented in this paper. It appears that the predicted stabilisation of the core temperatures at ∼ 2200 0 C may be a consequence of the artificially large spacing between the radial rings employed in the MIMAS code, rather than a result of physical significance. (author)

X-radiation effect on water transport in ascite cells of Ehrlich carcinoma

International Nuclear Information System (INIS)

Barnov, V.A.; Ajvazishvili, M.A.; Kartvelishvili, I.I.; Tushishvili, D.I.

1988-01-01

Effect of local X radiation with doses 0.05 and 0.15 C/kg on water transport in ascitic cells of Erlich carcinoma is studied in rats. To study water transport through cell membranes, tritium mark was used. It is concluded that radiation effect on water transport in cells of Erlich carcinoma may be related to change in ionic permittivity of the membrane, because small changes in transmembrane ion transport affect immediately the osmotic motion of water. 5 refs

Trade and transport of radiation sources

International Nuclear Information System (INIS)

1996-01-01

The guide specifies the obligations pertaining to the trade in and transport of radiation sources and other matters to be taken into account in safety supervision. It also specifies obligations and procedures relating to transfrontier movements of radioactive waste contained in the EU Council Directive 92/3/Euratom. (7 refs.)

Radiological emergency: road map for radiation accident victim transport; Emergência radiológica: roadmap para o transporte de radioacidentado

Energy Technology Data Exchange (ETDEWEB)

Costa, V.S.G.; Alcantara, Y.P. [Faculdade Casa Branca, SP (Brazil); Lima, C.M.A. [MAXIM Cursos, Rio de Janeiro, RJ (Brazil); Silva, F. C. A. da, E-mail: franciscodasilva13uk@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

During a radiological or nuclear emergency, a number of necessary actions are taken, both within the radiation protection of individuals and the environment, involving many institutions and highly specialized personnel. Among them it is possible to emphasize the air transportation of radiation accident victims.The procedures and measures for the safe transport of these radiation accident victims are generally the responsibility of the armed forces, specifically the Aeronautics, with the action denominated 'Aeromedical Military Evacuation of Radiation Accident Victims'. The experience with the Radiological Accident of Goiânia demonstrated the importance of adequate preparation and response during a radiological emergency and the need for procedures and measures with regard to the transport of radiation victims are clearly defined and clearly presented for the effectiveness of the actions. This work presents the necessary actions for the transport of radiation accident victim during a radiological emergency, through the road map technique, which has been widely used in scientific technical area to facilitate understanding and show the way to be followed to reach the proposed objectives.

Estimated routine radiation doses to transportation workers in alternative spent-fuel transportation systems

International Nuclear Information System (INIS)

Schneider, K.J.; Smith, R.I.; Daling, P.M.; Ross, W.A.; McNair, G.W.

1988-01-01

The federal system for the management of spent fuel and high-level radioactive waste includes the acceptance by the US Department of Energy (DOE) of the spent fuel or waste loaded in casks at the reactor or other waste generators, its transportation to a repository, and its handling and final emplacement in the repository. The DOE plans to implement a transportation system that is safe, secure, efficient, and cost-effective and will meet applicable regulatory safety and security requirements. The DOE commissioned the Pacific Northwest Laboratory (PNL) to develop estimates of the routine radiation doses that would result from the operation of a system postulated using current designs and practices. From that evaluation, PNL identified activities/operations that result in the higher fraction of doses, proposed conceptual alternatives that would effectively reduce such exposures, and evaluated the cost-effectiveness of such alternatives. The study is one of a series used in making overall system design and operational decisions in the development of the DOE's spent-fuel/high-level waste transportation system. This paper contains the highlights from the PNL study of the estimated radiation doses to the transportation workers in a postulated reference transportation system and potential alternatives to that system

Radiation transport effects in divertor plasmas generated during a tokamak reactor disruption

International Nuclear Information System (INIS)

Peterson, R.R.; MacFarlane, J.J.; Wang, P.

1994-01-01

Vaporization of material from tokamak divertors during disruptions is a critical issue for tokamak reactors from ITER to commercial power plants. Radiation transport from the vaporized material onto the remaining divertor surface plays an important role in the total mass loss to the divertor. Radiation transport in such a vapor is very difficult to calculate in full detail, and this paper quantifies the sensitivity of the divertor mass loss to uncertainties in the radiation transport. Specifically, the paper presents the results of computer simulations of the vaporization of a graphite coated divertor during a tokamak disruption with ITER CDA parameters. The results show that a factor of 100 change in the radiation conductivity changes the mass loss by more than a factor of two

bhlight: GENERAL RELATIVISTIC RADIATION MAGNETOHYDRODYNAMICS WITH MONTE CARLO TRANSPORT

International Nuclear Information System (INIS)

Ryan, B. R.; Gammie, C. F.; Dolence, J. C.

2015-01-01

We present bhlight, a numerical scheme for solving the equations of general relativistic radiation magnetohydrodynamics using a direct Monte Carlo solution of the frequency-dependent radiative transport equation. bhlight is designed to evolve black hole accretion flows at intermediate accretion rate, in the regime between the classical radiatively efficient disk and the radiatively inefficient accretion flow (RIAF), in which global radiative effects play a sub-dominant but non-negligible role in disk dynamics. We describe the governing equations, numerical method, idiosyncrasies of our implementation, and a suite of test and convergence results. We also describe example applications to radiative Bondi accretion and to a slowly accreting Kerr black hole in axisymmetry

3D-TRANS-2003, Workshop on Common Tools and Interfaces for Radiation Transport Codes

International Nuclear Information System (INIS)

2004-01-01

Description: Contents proceedings of Workshop on Common Tools and Interfaces for Deterministic Radiation Transport, for Monte Carlo and Hybrid Codes with a proposal to develop the following: GERALD - A General Environment for Radiation Analysis and Design. GERALD intends to create a unifying software environment where the user can define, solve and analyse a nuclear radiation transport problem using available numerical tools seamlessly. This environment will serve many purposes: teaching, research, industrial needs. It will also help to preserve the existing analytical and numerical knowledge base. This could represent a significant step towards solving the legacy problem. This activity should contribute to attracting young engineers to nuclear science and engineering and contribute to competence and knowledge preservation and management. This proposal was made at the on Workshop on C ommon Tools and Interfaces for Deterministic Radiation Transport, for Monte Carlo and Hybrid Codes , held from 25-26 September 2003 in connection with the conference SNA-2003. A first success with the development of such tools was achieved with the BOT3P2.0 and 3.0 codes providing an easy procedure and mechanism for defining and displaying 3D geometries and materials both in the form of refineable meshes for deterministic codes or Monte Carlo geometries consistent with deterministic models. Advanced SUSD: Improved tools for Sensitivity/Uncertainty Analysis. The development of tools for the analysis and estimation of sensitivities and uncertainties in calculations, or their propagation through complex computational schemes, in the field of neutronics, thermal hydraulics and also thermo-mechanics is of increasing importance for research and engineering applications. These tools allow establishing better margins for engineering designs and for the safe operation of nuclear facilities. Such tools are not sufficiently developed, but their need is increasingly evident in many activities

Radiation risk assessment for the transport of radioisotopes using KRI-BGM B(U) type container

International Nuclear Information System (INIS)

Cho, Woon-Kap

2008-01-01

The radiation risks were estimated for the transportation of radioisotopes using KRI-BGM transport container. KRI-BGM container was specially designed for transportation of large amount of radioisotopes for industrial or medical applications. The container can carry maximum 370 TBq of solid Ir-192, 29.6 TBq of liquid Mo-99 and 37 TBq of liquid I-131 respectively. For the radiation risk assessment, it was assumed that maximum design activity of those radioisotopes was transported. Transportation route is from Daejeon where radioisotopes are produced to Seoul where radioisotopes are consumed. Transport distance is 200 km including highway and downtown area from Daejeon to Seoul. As the transportation conveyance, an ordinary cargo truck is used exclusively. Radiation risks were estimated for incident free and accident condition of transportation and RADTRAN 5.6 was used as the risk assessment tool. For the risk assessment of radioisotopes transportation, various parameters such as population density around transport route, weather condition, probability of specific accidents such as impact, fire, etc. were considered. From the results of this study, the exclusive transportation of radioisotopes using KRI-BGM transport container by truck showed low radiological risks with manageable safety and health consequences. This paper discusses the methods and results of the radiation risks assessment for the radioisotopes transportation by an ordinary truck and presents the expected radiation risks in person-Sv and latent cancer fatalities. (author)

Integral and Lagrangian simulations of particle and radiation transport in plasma

International Nuclear Information System (INIS)

Christlieb, A J; Hitchon, W N G; Lawler, J E; Lister, G G

2009-01-01

Accurate integral and Lagrangian models of transport in plasmas, in which the models reflect the actual physical behaviour as closely as possible, are presented. These methods are applied to the behaviour of particles and photons in plasmas. First, to show how these types of models arise in a wide range of plasma physics applications, an application to radiation transport in a lighting discharge is given. The radiation transport is solved self-consistently with a model of the discharge to provide what are believed to be very accurate 1D simulations of fluorescent lamps. To extend these integral methods to higher dimensions is computationally very costly. The wide utility of 'treecodes' in solving massive integral problems in plasma physics is discussed, and illustrated in modelling vortex formation in a Penning trap, where a remarkably detailed simulation of vortex formation in the trap is obtained. Extension of treecode methods to other integral problems such as radiation transport is under consideration.

Fallout radiation protection provided by transportation vehicles

Energy Technology Data Exchange (ETDEWEB)

Burson, Z.G.

1972-10-20

Fallout radiation protection factors (PF's) were estimated for a variety of civilian transportation vehicles using measurements of the natural terrain radiation as a source. The PF values are below 2 in light vehicles, truck beds, or trailers; from 2.5 to 3 in the cabs of heavy trucks and in a railway guard car; and from 3.0 to 3.5 in the engineer's seat of heavy locomotives. This information can be useful in planning the possible movement of personnel from or through areas contaminated either by a wartime incident or a peacetime accident. The information may also be useful for studying the reduction of exposure to the natural terrestrial radiation environment provided by vehicles.

VU-B radiation inhibits the photosynthetic electron transport chain in chlamydomonas reinhardtii

International Nuclear Information System (INIS)

Cai, W.; Li, X.; Chen, L.

2016-01-01

UV radiation of sunlight is one of harmful factors for earth organisms, especially for photoautotrophs because they require light for energy and biomass production. A number of works have already been done regarding the effects of UV-B radiation at biochemical and molecular level, which showed that UV-B radiation could inhibit photosynthesis activity and reduce photosynthetic electron transport. However quite limited information can accurately make out inhibition site of UV-B radiation on photosynthetic electron transport. In this study, this issue was investigated through measuring oxygen evolution activity, chlorophyll a fluorescence and gene expression in a model unicellular green alga Chlamydomonas reinhardtii. Our results indicated that UV-B radiation could evidently decrease photosynthesis activity and inhibit electron transport by blocking electron transfer process from the first plastoquinone electron acceptors QA to second plastoquinone electron acceptors QB, but not impair electron transfer from the water oxidizing complex to QA. The psbA gene expression was also altered by UV-B radiation, where up-regulation occurred at 2, 4 and 6h after exposure and down-regulation happened at 12 and 24 h after exposure. These results suggested that UV-B could affects D1 protein normal turnover, so there was not enough D1 for binding with QB, which may affect photosynthetic electron transport and photosynthesis activity. (author)

Process and appliance for determining the nature of transported substances by measuring the radiations transmitted

International Nuclear Information System (INIS)

Wykes, J.S.; Surzyn, P.M.; Croke, G.M.; Adsley, Ian.

1980-01-01

The invention relates to a process for determining the nature of a substance transported, comprising the collimation of the radiation of not less than two energies so that they form beams; the irradiation of the matter transported by the beams, the detection of the non-scattered radiations for the two energies at least, after passing in the transported matter, and the deduction of the nature of the transported matter according to the radiations detected. The radiations are collimated by placing a shield around the gamma source (americium 241 or cesium 137). The detector is protected by a shield so that it prevents any significant interference due to the reactions near the surface provoked by those radiations not of the lowest energy, with detection of those radiations of lesser energy. In a variation, a source of relatively higher energy radiations is placed at a distance from the source of relatively lesser energy radiations. The latter have a component taken from natural ionizing radiation and this component is withdrawn to a predetermined calibration [fr

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 1, August 2012

International Nuclear Information System (INIS)

2012-08-01

The IAEA has a statutory function to establish standards for the protection of health, life and property against ionizing radiation and to provide for the application of these standards to peaceful nuclear activities. Education and training (E and T) is one of the main mechanisms to provide support to Member States in the application of the standards. In 2000, an internal evaluation of the overall education and training programme was undertaken. The conclusions were that the provision of and support for E and T in Member States tended to be on a reactive rather than proactive basis, contributing to a culture of dependency rather than sustainability. On the basis of this evaluation, a strategic approach to education and training in radiation and waste safety was developed that outlined the objectives and outcomes to be achieved over a ten year period (2001-2010). General Conference Resolutions have underlined or emphasized the importance of sustainable programmes for education and training in radiation, transport and waste safety, and have also welcomed the ongoing commitment of the Secretariat and Member States to the implementation of the strategy. A Steering Committee for Education and Training in Radiation Protection and Waste Safety was established in 2002, with the mission of advising the IAEA on the implementation of the strategy and making recommendations as appropriate. In 2010, the Steering Committee analysed the overall achievement of the strategic approach 2011-2010, refined the vision of the original strategy and redefined the related objectives. The Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) was submitted to the IAEA's policy-making organs and was noted by its Board of Governors in September 2010.

Radiation exposures of workers and the public associated with the transport of radioactive material in Germany

International Nuclear Information System (INIS)

Schwarz, G.; Fett, H.J.; Lange, F.

2004-01-01

Most radioactive material packages transported emit penetrating ionising radiation and radiation exposures of transport workers and the public may occur during their transport. The radiation exposures incurred by transport workers and members of the public can vary significantly depending on a number of factors: most important is the type of radiation emitted (primarily gamma and neutron radiation), the radiation field intensity in the surrounding of a package and conveyance and the duration of exposure to ionising radiation. The information and guidance material on occupational exposures has primarily been derived from a survey and analysis of personal monitoring data provided by a number of commercial transport operators in Germany known as major carrier and handler organisations of fuel cycle and non-fuel cycle material (in terms of the number of pack-ages and the activity carriaged). To some extent advantage was taken of compilations of statistical transport and exposure data collated within other transport safety analysis studies including research projects funded by the European Commission. The exposure data collected cover the time period of the last 4 - 8 years and are most representative for routine transport operations closely related to the movement phase of packaged radioactive material, i.e. receipt, vehicle loading, carriage, in-transit storage, intra-/intermodal transfer, vehicle unloading and delivery at the final destination of loads of radioactive material and packages and the related supervisory and health physics functions. Radiation dose monitoring of members of the public, however, is generally impracticable and, consequently, the information available relies on employing dose assessment models and reflects radiation exposures incurred by hypothetical or critical group individuals of members of the public under normal conditions of transport

Economic analyses in health care: an introduction to the methodology with an emphasis on radiation therapy

International Nuclear Information System (INIS)

Hayman, James; Weeks, Jane; Mauch, Peter

1996-01-01

Payers are increasingly interested in knowing whether they are receiving value for the dollars they spend on health care. Because economic analyses will be used as a means of evaluating radiation therapy, it is important that radiation oncologists understand the basic methodology employed in such analyses. This review article describes the four basic types of economic analyses: cost minimization, cost effectiveness, cost utility, and cost benefit. Specification of alternative therapies, choice of perspective of the analysis, measurements of costs and benefits, and the role of discounting and sensitivity analyses are discussed. Published economic analyses that pertain directly to treatment with radiation therapy are reviewed. Finally, we close with a brief discussion of the potential areas for future economic outcomes research in radiation oncology

Interface methods for hybrid Monte Carlo-diffusion radiation-transport simulations

International Nuclear Information System (INIS)

Densmore, Jeffery D.

2006-01-01

Discrete diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Monte Carlo simulations in diffusive media. An important aspect of DDMC is the treatment of interfaces between diffusive regions, where DDMC is used, and transport regions, where standard Monte Carlo is employed. Three previously developed methods exist for treating transport-diffusion interfaces: the Marshak interface method, based on the Marshak boundary condition, the asymptotic interface method, based on the asymptotic diffusion-limit boundary condition, and the Nth-collided source technique, a scheme that allows Monte Carlo particles to undergo several collisions in a diffusive region before DDMC is used. Numerical calculations have shown that each of these interface methods gives reasonable results as part of larger radiation-transport simulations. In this paper, we use both analytic and numerical examples to compare the ability of these three interface techniques to treat simpler, transport-diffusion interface problems outside of a more complex radiation-transport calculation. We find that the asymptotic interface method is accurate regardless of the angular distribution of Monte Carlo particles incident on the interface surface. In contrast, the Marshak boundary condition only produces correct solutions if the incident particles are isotropic. We also show that the Nth-collided source technique has the capacity to yield accurate results if spatial cells are optically small and Monte Carlo particles are allowed to undergo many collisions within a diffusive region before DDMC is employed. These requirements make the Nth-collided source technique impractical for realistic radiation-transport calculations

Regulatory practices of radiation safety of SNF transportation in Russia

International Nuclear Information System (INIS)

Kuryndina, Lidia; Kuryndin, Anton; Stroganov, Anatoly

2008-01-01

This paper overviews current regulatory practices for the assurance of nuclear and radiation safety during railway transportation of SNF on the territory of Russian Federation from NPPs to longterm-storage of reprocessing sites. The legal and regulatory requirements (mostly compliant with IAEA ST-1), licensing procedure for NM transportation are discussed. The current procedure does not require a regulatory approval for each particular shipment if the SNF fully comply with the Rosatom's branch standard and is transported in approved casks. It has been demonstrated that SNF packages compliant with the branch standard, which is knowingly provide sufficient safety margin, will conform to the federal level regulations. The regulatory approval is required if a particular shipment does not comply with the branch standard. In this case, the shipment can be approved only after regulatory review of Applicant's documents to demonstrate that the shipment still conformant to the higher level (federal) regulations. The regulatory review frequently needs a full calculation test of the radiation safety assurance. This test can take a lot of time. That's why the special calculation tools were created in SEC NRS. These tools aimed for precision calculation of the radiation safety parameters by SNF transportation use preliminary calculated Green's functions. Such approach allows quickly simulate any source distribution and optimize spent fuel assemblies placement in cask due to the transport equation property of linearity relatively the source. The short description of calculation tools are presented. Also, the paper discusses foreseen implications related to transportation of mixed-oxide SNF. (author)

The radiation analyses of ITER lower ports

International Nuclear Information System (INIS)

Petrizzi, L.; Brolatti, G.; Martin, A.; Loughlin, M.; Moro, F.; Villari, R.

2010-01-01

The ITER Vacuum Vessel has upper, equatorial, and lower ports used for equipment installation, diagnostics, heating and current drive systems, cryo-vacuum pumping, and access inside the vessel for maintenance. At the level of the divertor, the nine lower ports for remote handling, cryo-vacuum pumping and diagnostic are inclined downwards and toroidally located each every 40 o . The cryopump port has additionally a branch to allocate a second cryopump. The ports, as openings in the Vacuum Vessel, permit radiation streaming out of the vessel which affects the heating in the components in the outer regions of the machine inside and outside the ports. Safety concerns are also raised with respect to the dose after shutdown at the cryostat behind the ports: in such zones the radiation dose level must be kept below the regulatory limit to allow personnel access for maintenance purposes. Neutronic analyses have been required to qualify the ITER project related to the lower ports. A 3-D model was used to take into account full details of the ports and the lower machine surroundings. MCNP version 5 1.40 has been used with the FENDL 2.1 nuclear data library. The ITER 40 o model distributed by the ITER Organization was developed in the lower part to include the relevant details. The results of a first analysis, focused on cryopump system only, were recently published. In this paper more complete data on the cryopump port and analysis for the remote handling port and the diagnostic rack are presented; the results of both analyses give a complete map of the radiation loads in the outer divertor ports. Nuclear heating, dpa, tritium production, and dose rates after shutdown are provided and the implications for the design are discussed.

Hybrid formulation of radiation transport in optically thick divertor plasmas

Energy Technology Data Exchange (ETDEWEB)

Rosato, J.; Marandet, Y.; Bufferand, H.; Stamm, R. [PIIM, UMR 7345 Aix-Marseille Universite / CNRS, Centre de St-Jerome, Marseille (France); Reiter, D. [IEK-4 Plasmaphysik, Forschungszentrum Juelich GmbH, Juelich (Germany)

2016-08-15

Kinetic Monte Carlo simulations of coupled atom-radiation transport in optically thick divertor plasmas can be computationally very demanding, in particular in ITER relevant conditions or even larger devices, e.g. for power plant divertor studies. At high (∝ 10{sup 15} cm{sup -3}) atomic densities, it can be shown that sufficiently large divertors behave in certain areas like a black body near the first resonance line of hydrogen (Lyman α). This suggests that, at least in part, the use of continuum model (radiation hydrodynamics) can be sufficiently accurate, while being less time consuming. In this work, we report on the development of a hybrid model devoted to switch automatically between a kinetic and a continuum description according to the plasma conditions. Calculations of the photo-excitation rate in a homogeneous slab are performed as an illustration. The outlined hybrid concept might be also applicable to neutral atom transport, due to mathematical analogy of transport equations for neutrals and radiation. (copyright 2016 The Authors. Contributions to Plasma Physics published by Wiley-VCH Verlag GmbH and Co. KGaA Weinheim. This)

Radiation Belt Transport Driven by Solar Wind Dynamic Pressure Fluctuations

Science.gov (United States)

Kress, B. T.; Hudson, M. K.; Ukhorskiy, A. Y.; Mueller, H.

2012-12-01

The creation of the Earth's outer zone radiation belts is attributed to earthward transport and adiabatic acceleration of electrons by drift-resonant interactions with electromagnetic fluctuations in the magnetosphere. Three types of radial transport driven by solar wind dynamic pressure fluctuations that have been identified are: (1) radial diffusion [Falthammer, 1965], (2) significant changes in the phase space density radial profile due to a single or few ULF drift-resonant interactions [Ukhorskiy et al., 2006; Degeling et al., 2008], and (3) shock associated injections of radiation belt electrons occurring in less than a drift period [Li et al., 1993]. A progress report will be given on work to fully characterize different forms of radial transport and their effect on the Earth's radiation belts. The work is being carried out by computing test-particle trajectories in electric and magnetic fields from a simple analytic ULF field model and from global MHD simulations of the magnetosphere. Degeling, A. W., L. G. Ozeke, R. Rankin, I. R. Mann, and K. Kabin (2008), Drift resonant generation of peaked relativistic electron distributions by Pc 5 ULF waves, textit{J. Geophys. Res., 113}, A02208, doi:10.1029/2007JA012411. Fälthammar, C.-G. (1965), Effects of Time-Dependent Electric Fields on Geomagnetically Trapped Radiation, J. Geophys. Res., 70(11), 2503-2516, doi:10.1029/JZ070i011p02503. Li, X., I. Roth, M. Temerin, J. R. Wygant, M. K. Hudson, and J. B. Blake (1993), Simulation of the prompt energization and transport of radiation belt particles during the March 24, 1991 SSC, textit{Geophys. Res. Lett., 20}(22), 2423-2426, doi:10.1029/93GL02701. Ukhorskiy, A. Y., B. J. Anderson, K. Takahashi, and N. A. Tsyganenko (2006), Impact of ULF oscillations in solar wind dynamic pressure on the outer radiation belt electrons, textit{Geophys. Res. Lett., 33}(6), L06111, doi:10.1029/2005GL024380.

The use of symbolic computation in radiative, energy, and neutron transport calculations

Science.gov (United States)

Frankel, J. I.

This investigation uses symbolic computation in developing analytical methods and general computational strategies for solving both linear and nonlinear, regular and singular, integral and integro-differential equations which appear in radiative and combined mode energy transport. This technical report summarizes the research conducted during the first nine months of the present investigation. The use of Chebyshev polynomials augmented with symbolic computation has clearly been demonstrated in problems involving radiative (or neutron) transport, and mixed-mode energy transport. Theoretical issues related to convergence, errors, and accuracy have also been pursued. Three manuscripts have resulted from the funded research. These manuscripts have been submitted to archival journals. At the present time, an investigation involving a conductive and radiative medium is underway. The mathematical formulation leads to a system of nonlinear, weakly-singular integral equations involving the unknown temperature and various Legendre moments of the radiative intensity in a participating medium. Some preliminary results are presented illustrating the direction of the proposed research.

Radiation exposures of workers resulting from the transport of gamma radiography sources in Germany

International Nuclear Information System (INIS)

Sentuc, F.N.; Schwarz, G.

2006-01-01

Gamma radiation sources are widely used for industrial purposes e.g. for non-destructive material testing. Many of these sources are permanently installed at a facility within instruments e.g. for level or thickness gauging. Other radioactive sources are implemented in portable devices for industrial gamma radiography which have to be carried to the various remote usage sites. In Germany, approximately 20 000 - 25 000 shipments of gamma radiography sources are proceeding annually on public transport routes. Since routine radiation monitoring programmes do not permit task-specific determination of occupational doses e.g. doses incurred during the movement phase and handling related doses, work has been carried out with the objective to determine the radiation exposures of the personnel attributable to transportation. For this purpose, a survey was launched in 2005 collecting data about e.g. the number and conditions of transports, the activity and type of transported radiation sources and the radiation level within the driver's cab to allow a dose assessment to be made for transport workers. The results of this survey covering the most important companies for gamma radiography services in Germany are presented in this paper. (authors)

Chemical and kinetic equilibrations via radiative parton transport

International Nuclear Information System (INIS)

Zhang Bin; Wortman, Warner A

2011-01-01

A hot and dense partonic system can be produced in the early stage of a relativistic heavy ion collision. How it equilibrates is important for the extraction of Quark-Gluon Plasma properties. We study the chemical and kinetic equilibrations of the Quark-Gluon Plasma using a radiative transport model. Thermal and Color-Glass-Condensate motivated initial conditions are used. We observe that screened parton interactions always lead to partial pressure isotropization. Different initial pressure anisotropies result in the same asymptotic evolution. Comparison of evolutions with and without radiative processes shows that chemical equilibration interacts with kinetic equilibration and radiative processes can contribute significantly to pressure isotropization.

Factors affecting radiation doses from dedicated rail transport of spent reactor fuel

International Nuclear Information System (INIS)

Martin, J.E.

1988-01-01

This paper reports there are two exposure control concerns associated with the shipment of spent reactor fuel in dedicated trains -- compliance with transportation regulations for maximum allowable radiation levels, and minimizing the dose received by the general public. This article examines the methods used to calculate the dose equivalent rates alongside stationary (transport regulations) and moving trains (public exposure) of various lengths. The factors examined include the source term, the effect of overlapping radiation fields, the speed of the train, and the location of the population relative to the train. Trains made up of series of cars that individually meet transport regulations can, as a whole, exceed transport vehicle dose equivalent rate limits by up to 23% due to overlapping radiation fields. For moving trains and the worst case analyzed -- a person located 20 feet from the tracks and a train speed of 5 mph --- 141 rail cars would have to pass by to deliver a dose equivalent of 1 mrem

Higher-fidelity yet efficient modeling of radiation energy transport through three-dimensional clouds

International Nuclear Information System (INIS)

Hall, M.L.; Davis, A.B.

2005-01-01

Accurate modeling of radiative energy transport through cloudy atmospheres is necessary for both climate modeling with GCMs (Global Climate Models) and remote sensing. Previous modeling efforts have taken advantage of extreme aspect ratios (cells that are very wide horizontally) by assuming a 1-D treatment vertically - the Independent Column Approximation (ICA). Recent attempts to resolve radiation transport through the clouds have drastically changed the aspect ratios of the cells, moving them closer to unity, such that the ICA model is no longer valid. We aim to provide a higher-fidelity atmospheric radiation transport model which increases accuracy while maintaining efficiency. To that end, this paper describes the development of an efficient 3-D-capable radiation code that can be easily integrated into cloud resolving models as an alternative to the resident 1-D model. Applications to test cases from the Intercomparison of 3-D Radiation Codes (I3RC) protocol are shown

Transport analysis of high radiation and high density plasmas in the ASDEX Upgrade tokamak

Directory of Open Access Journals (Sweden)

Casali L.

2014-01-01

Full Text Available Future fusion reactors, foreseen in the “European road map” such as DEMO, will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, DEMO will have to work at high core densities to reach adequate fusion performance. The performance of fusion reactors depends on three essential parameters: temperature, density and energy confinement time. The latter characterizes the loss rate due to both radiation and transport processes. The DEMO foreseen scenarios described above were not investigated so far, but are now addressed at the ASDEX Upgrade tokamak. In this work we present the transport analysis of such scenarios. Plasma with high radiation by impurity seeding: transport analysis taking into account the radiation distribution shows no change in transport during impurity seeding. The observed confinement improvement is an effect of higher pedestal temperatures which extend to the core via stiffness. A non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. High density plasmas with pellets: the analysis of kinetic profiles reveals a transient phase at the start of the pellet fuelling due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.

To the development of numerical methods in problems of radiation transport

International Nuclear Information System (INIS)

Germogenova, T.A.

1990-01-01

Review of studies on the development of numerical methods and the discrete ordinate method in particular, used for solution of radiation protection physics problems is given. Consideration is given to the problems, which arise when calculating fields of penetrating radiation and when studying processes of charged-particle transport and cascade processes, generated by high-energy primary radiation

The use of Monte Carlo radiation transport codes in radiation physics and dosimetry

CERN Multimedia

CERN. Geneva; Ferrari, Alfredo; Silari, Marco

2006-01-01

Transport and interaction of electromagnetic radiation Interaction models and simulation schemes implemented in modern Monte Carlo codes for the simulation of coupled electron-photon transport will be briefly reviewed. In these codes, photon transport is simulated by using the detailed scheme, i.e., interaction by interaction. Detailed simulation is easy to implement, and the reliability of the results is only limited by the accuracy of the adopted cross sections. Simulations of electron and positron transport are more difficult, because these particles undergo a large number of interactions in the course of their slowing down. Different schemes for simulating electron transport will be discussed. Condensed algorithms, which rely on multiple-scattering theories, are comparatively fast, but less accurate than mixed algorithms, in which hard interactions (with energy loss or angular deflection larger than certain cut-off values) are simulated individually. The reliability, and limitations, of electron-interacti...

Summary of Prometheus Radiation Shielding Nuclear Design Analyses , for information

International Nuclear Information System (INIS)

J. Stephens

2006-01-01

This report transmits a summary of radiation shielding nuclear design studies performed to support the Prometheus project. Together, the enclosures and references associated with this document describe NRPCT (KAPL and Bettis) shielding nuclear design analyses done for the project

Radiation doses due to long-range transport of airborne radionuclides

International Nuclear Information System (INIS)

Nordlund, G.; Valkama, I.; Rossi, J.; Savolainen, I.

1985-12-01

Within the framework of this study a model for estimating the long range transport of radioactive material and for calculating the resultant doses is developed. In the model initially the dispersion paths, i.e. trajectories, of the radioactive matter are calculated from the assumed source areas as well as the dispersion conditions along the trajectories. The trajectories are calculated at three-hour intervals in a two-dimensional grid using numerically analysed winds at a constant pressure level of 850 mb. The dispersion condition parameters applied are: the stability of the atmospheric boundary layer, the so-called mixing height, occurrence of precipitation and the character of the terrain. For each trajectory a type-index value is computed, describing the severity of the possible effects of radioactivity transported by the particular trajectory. The dispersion model uses the information on dispersion conditions provided by the trajectory model to compute the remaining radioactivity in the cloud, the deposition, as well as the doses due to different dose pathways. The pathways used are the external radiation from the cloud and from the activity deposited on the ground, inhalation of radioactive material and ingestion of contaminated food products (milk, meat, green vegetables, grain and roots). In addition to the effects of individual transport incidents, the cumulative probability distributions of the effects of accidental releases of radioactive matter can also be calculated using trajectory statistics and the trajectory type index

Activities of the Radiation Shielding Information Center and a report on codes/data for high energy radiation transport

International Nuclear Information System (INIS)

Roussin, R.W.

1993-01-01

From the very early days in its history Radiation Shielding Information Center (RSIC) has been involved with high energy radiation transport. The National Aeronautics and Space Administration was an early sponsor of RSIC until the completion of the Apollo Moon Exploration Program. In addition, the intranuclear cascade work of Bertini at Oak Ridge National Laboratory provided valuable resources which were made available through RSIC. Over the years, RSIC has had interactions with many of the developers of high energy radiation transport computing technology and data libraries and has been able to collect and disseminate this technology. The current status of this technology will be reviewed and prospects for new advancements will be examined

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2c, May 2013

International Nuclear Information System (INIS)

2013-05-01

The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Europe via the Regional Project RER/9/109 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. IAEA's Regional Training Centres (RTCs) in Greece and Belarus are key partners in the European region.

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2d, June 2013

International Nuclear Information System (INIS)

2013-06-01

The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Latin America via the Regional Project RLA/9/070 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. IAEA's Regional Training Centres (RTCs) in Argentina and Brazil are key partners in the Latin-American region.

Monte Carlo method in radiation transport problems

International Nuclear Information System (INIS)

Dejonghe, G.; Nimal, J.C.; Vergnaud, T.

1986-11-01

In neutral radiation transport problems (neutrons, photons), two values are important: the flux in the phase space and the density of particles. To solve the problem with Monte Carlo method leads to, among other things, build a statistical process (called the play) and to provide a numerical value to a variable x (this attribution is called score). Sampling techniques are presented. Play biasing necessity is proved. A biased simulation is made. At last, the current developments (rewriting of programs for instance) are presented due to several reasons: two of them are the vectorial calculation apparition and the photon and neutron transport in vacancy media [fr

Implicit Monte Carlo methods and non-equilibrium Marshak wave radiative transport

International Nuclear Information System (INIS)

Lynch, J.E.

1985-01-01

Two enhancements to the Fleck implicit Monte Carlo method for radiative transport are described, for use in transparent and opaque media respectively. The first introduces a spectral mean cross section, which applies to pseudoscattering in transparent regions with a high frequency incident spectrum. The second provides a simple Monte Carlo random walk method for opaque regions, without the need for a supplementary diffusion equation formulation. A time-dependent transport Marshak wave problem of radiative transfer, in which a non-equilibrium condition exists between the radiation and material energy fields, is then solved. These results are compared to published benchmark solutions and to new discrete ordinate S-N results, for both spatially integrated radiation-material energies versus time and to new spatially dependent temperature profiles. Multigroup opacities, which are independent of both temperature and frequency, are used in addition to a material specific heat which is proportional to the cube of the temperature. 7 refs., 4 figs

Radiation safety of crew and passengers of air transportation in civil aviation. Provisional standards

Science.gov (United States)

Aksenov, A. F.; Burnazyan, A. I.

1985-01-01

The purpose and application of the provisional standards for radiation safety of crew and passengers in civil aviation are given. The radiation effect of cosmic radiation in flight on civil aviation air transport is described. Standard levels of radiation and conditions of radiation safety are discussed.

Radiation transport in high-level waste form

International Nuclear Information System (INIS)

Arakali, V.S.; Barnes, S.M.

1992-01-01

The waste form selected for vitrifying high-level nuclear waste stored in underground tanks at West Valley, NY is borosilicate glass. The maximum radiation level at the surface of a canister filled with the high-level waste form is prescribed by repository design criteria for handling and disposition of the vitrified waste. This paper presents an evaluation of the radiation transport characteristics for the vitreous waste form expected to be produced at West Valley and the resulting neutron and gamma dose rates. The maximum gamma and neutron dose rates are estimated to be less than 7500 R/h and 10 mRem/h respectively at the surface of a West Valley canister filled with borosilicate waste glass

Self-consistent collisional-radiative model for hydrogen atoms: Atom–atom interaction and radiation transport

International Nuclear Information System (INIS)

Colonna, G.; Pietanza, L.D.; D’Ammando, G.

2012-01-01

Graphical abstract: Self-consistent coupling between radiation, state-to-state kinetics, electron kinetics and fluid dynamics. Highlight: ► A CR model of shock-wave in hydrogen plasma has been presented. ► All equations have been coupled self-consistently. ► Non-equilibrium electron and level distributions are obtained. ► The results show non-local effects and non-equilibrium radiation. - Abstract: A collisional-radiative model for hydrogen atom, coupled self-consistently with the Boltzmann equation for free electrons, has been applied to model a shock tube. The kinetic model has been completed considering atom–atom collisions and the vibrational kinetics of the ground state of hydrogen molecules. The atomic level kinetics has been also coupled with a radiative transport equation to determine the effective adsorption and emission coefficients and non-local energy transfer.

Deterministic methods in radiation transport. A compilation of papers presented February 4--5, 1992

Energy Technology Data Exchange (ETDEWEB)

Rice, A.F.; Roussin, R.W. [eds.

1992-06-01

The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

Deterministic methods in radiation transport. A compilation of papers presented February 4-5, 1992

Energy Technology Data Exchange (ETDEWEB)

Rice, A. F.; Roussin, R. W. [eds.

1992-06-01

The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

Rare event simulation in radiation transport

International Nuclear Information System (INIS)

Kollman, C.

1993-10-01

This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved, even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiple by the likelihood ratio between the true and simulated probabilities so as to keep the estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive ''learning'' algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give with probability one, a sequence of estimates converging exponentially fast to the true solution

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2b, May 2013

International Nuclear Information System (INIS)

2013-05-01

The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Asia and the Pacific via the Regional project RAS/9/066 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. IAEA's Regional Training Centres (RTCs) in Malaysia and Syrian Arabic Republic are key partners in the Asian and the Pacific region.

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 2a, May 2013

International Nuclear Information System (INIS)

2013-05-01

The IAEA Strategic Approach to Education and Training in Radiation, Transport and Waste Safety (2011-2020) provides a framework for establishing a sustainable education and training infrastructure in Member States that addresses national needs for building and maintaining competence in radiation, transport and waste safety that is consistent with IAEA Safety Standards. For this purpose, IAEA's General Conference has encouraged Member States to develop a national strategy for education and training, underlining the fundamental importance of sustainable programmes for building competence in radiation, transport and waste safety, as a key component of safety infrastructure. Furthermore Member States that receive assistance from IAEA are obliged to apply IAEA Safety Standards which require, inter alia, governments to establish a national policy and strategy for safety, including provisions for acquiring and maintaining the necessary competence nationally for ensuring safety. IAEA's Division of Radiation, Transport and Waste Safety is assisting Member States to develop their own national strategies in Africa via the Regional project RAF/9/04 on ''Strengthening Education and training Infrastructure, and Building Competence in Radiation Safety'', which includes, inter alia, Regional Workshops on National Strategies for education and training in radiation transport and waste safety. AFRA Regional Designated Centres, in Algeria, Ghana and Morocco, equivalent to the IAEA's Regional Training Centres (RTCs) present in all the other regions, are key partners in the African region.

Transport-constrained extensions of collision and track length estimators for solutions of radiative transport problems

International Nuclear Information System (INIS)

Kong, Rong; Spanier, Jerome

2013-01-01

In this paper we develop novel extensions of collision and track length estimators for the complete space-angle solutions of radiative transport problems. We derive the relevant equations, prove that our new estimators are unbiased, and compare their performance with that of more conventional estimators. Such comparisons based on numerical solutions of simple one dimensional slab problems indicate the the potential superiority of the new estimators for a wide variety of more general transport problems

Gray and multigroup radiation transport models for two-dimensional binary stochastic media using effective opacities

International Nuclear Information System (INIS)

Olson, Gordon L.

2016-01-01

One-dimensional models for the transport of radiation through binary stochastic media do not work in multi-dimensions. Authors have attempted to modify or extend the 1D models to work in multidimensions without success. Analytic one-dimensional models are successful in 1D only when assuming greatly simplified physics. State of the art theories for stochastic media radiation transport do not address multi-dimensions and temperature-dependent physics coefficients. Here, the concept of effective opacities and effective heat capacities is found to well represent the ensemble averaged transport solutions in cases with gray or multigroup temperature-dependent opacities and constant or temperature-dependent heat capacities. In every case analyzed here, effective physics coefficients fit the transport solutions over a useful range of parameter space. The transport equation is solved with the spherical harmonics method with angle orders of n=1 and 5. Although the details depend on what order of solution is used, the general results are similar, independent of angular order. - Highlights: • Gray and multigroup radiation transport is done through 2D stochastic media. • Approximate models for the mean radiation field are found for all test problems. • Effective opacities are adjusted to fit the means of stochastic media transport. • Test problems include temperature dependent opacities and heat capacities • Transport solutions are done with angle orders n=1 and 5.

Small-sized linear accelerator of 2.5 MeV electrons with a local radiation shield for custom examination of freight transported by motor transport

International Nuclear Information System (INIS)

Baklanov, A.V.; Gavrish, Yu.N.; Klinov, A.P.; Krest'yaninov, A.S.; Nikolaev, V.M.; Fomin, L.P.; Linkenbach, H.A.; Geus, G.; Knospel, W.

2001-01-01

A new development of a small-sized linear accelerator of 2.5 MeV electrons with a local radiation protection is described. The accelerator is intended for movable facilities of radiation custom of the freight transported by motor transport. Main constructive solutions, mass and dimension characteristics and results of preliminary tests of the accelerator parameters and characteristics of radiation protection are presented [ru

Discussion of and guidance on the optimization of radiation protection in the transport of radioactive material

International Nuclear Information System (INIS)

1986-05-01

The document provides guidance on one of the components of the system of dose limitation as it applies to the transport of radioactive material, namely the optimization of radiation protection. It focuses on the following parts of the transport system: design, maintenance, preparation for transport, transport, storage-in-transit and handling and it considers occupational and public exposures. The application is intended mainly for those transport situations within the regulatory requirements where potential radiation exposures could be beneficially reduced

Radioactive materials' transportation main routes in Brazil. Radiation protection aspects about radioactive materials transportation

International Nuclear Information System (INIS)

Vaz, Solange dos Reis e; Andrade, Fernando de Menezes; Aleixo, Luiz Claudio Martins

2007-01-01

The heavy transportation in Brazil is generally done by highways. The radioactive material transportation follow this same rule. Whenever a radioactive material is carried by the road, by the sea or by the air, in some cases, a kind of combination of those transportation ways, the transport manager has to create a Transportation Plan and submit it to CNEN. Only after CNEN's approval, the transportation can be done. The plan must have the main action on Radiation Protection, giving responsibilities and showing all the directing that will be take. Although, the Brazilian's highways are not in good conditions, one could say that some of them are not good enough for any kind of transportation. But we are facing radioactive material use increase but the hospitals and industries, that the reason it's much more common that kind of transportation nowadays. So, because of that, a special attention by the governments must be provide to those activities. This paper goal is to show the real conditions of some important highways in Brazil in a radioactive protection's perspective and give some suggestions to adjust some of those roads to this new reality. (author)

AREVA Developments for an Efficient and Reliable use of Monte Carlo codes for Radiation Transport Applications

Science.gov (United States)

Chapoutier, Nicolas; Mollier, François; Nolin, Guillaume; Culioli, Matthieu; Mace, Jean-Reynald

2017-09-01

In the context of the rising of Monte Carlo transport calculations for any kind of application, AREVA recently improved its suite of engineering tools in order to produce efficient Monte Carlo workflow. Monte Carlo codes, such as MCNP or TRIPOLI, are recognized as reference codes to deal with a large range of radiation transport problems. However the inherent drawbacks of theses codes - laboring input file creation and long computation time - contrast with the maturity of the treatment of the physical phenomena. The goals of the recent AREVA developments were to reach similar efficiency as other mature engineering sciences such as finite elements analyses (e.g. structural or fluid dynamics). Among the main objectives, the creation of a graphical user interface offering CAD tools for geometry creation and other graphical features dedicated to the radiation field (source definition, tally definition) has been reached. The computations times are drastically reduced compared to few years ago thanks to the use of massive parallel runs, and above all, the implementation of hybrid variance reduction technics. From now engineering teams are capable to deliver much more prompt support to any nuclear projects dealing with reactors or fuel cycle facilities from conceptual phase to decommissioning.

Directions in Radiation Transport Modelling

Directory of Open Access Journals (Sweden)

P Nicholas Smith

2016-12-01

More exciting advances are on the horizon to increase the power of simulation tools. The advent of high performance computers is allowing bigger, higher fidelity models to be created, if the challenges of parallelization and memory management can be met. 3D whole core transport modelling is becoming possible. Uncertainty quantification is improving with large benefits to be gained from more accurate, less pessimistic estimates of uncertainty. Advanced graphical displays allow the user to assimilate and make sense of the vast amounts of data produced by modern modelling tools. Numerical solvers are being developed that use goal-based adaptivity to adjust the nodalisation of the system to provide the optimum scheme to achieve the user requested accuracy on the results, thus removing the need to perform costly convergence studies in space and angle etc. More use is being made of multi-physics methods in which radiation transport is coupled with other phenomena, such as thermal-hydraulics, structural response, fuel performance and/or chemistry in order to better understand their interplay in reactor cores.

Radiative transport equation for the Mittag-Leffler path length distribution

Science.gov (United States)

Liemert, André; Kienle, Alwin

2017-05-01

In this paper, we consider the radiative transport equation for infinitely extended scattering media that are characterized by the Mittag-Leffler path length distribution p (ℓ ) =-∂ℓEα(-σtℓα ) , which is a generalization of the usually assumed Lambert-Beer law p (ℓ ) =σtexp(-σtℓ ) . In this context, we derive the infinite-space Green's function of the underlying fractional transport equation for the spherically symmetric medium as well as for the one-dimensional string. Moreover, simple analytical solutions are presented for the prediction of the radiation field in the single-scattering approximation. The resulting equations are compared with Monte Carlo simulations in the steady-state and time domain showing, within the stochastic nature of the simulations, an excellent agreement.

NASA space radiation transport code development consortium

International Nuclear Information System (INIS)

Townsend, L. W.

2005-01-01

Recently, NASA established a consortium involving the Univ. of Tennessee (lead institution), the Univ. of Houston, Roanoke College and various government and national laboratories, to accelerate the development of a standard set of radiation transport computer codes for NASA human exploration applications. This effort involves further improvements of the Monte Carlo codes HETC and FLUKA and the deterministic code HZETRN, including developing nuclear reaction databases necessary to extend the Monte Carlo codes to carry out heavy ion transport, and extending HZETRN to three dimensions. The improved codes will be validated by comparing predictions with measured laboratory transport data, provided by an experimental measurements consortium, and measurements in the upper atmosphere on the balloon-borne Deep Space Test Bed (DSTB). In this paper, we present an overview of the consortium members and the current status and future plans of consortium efforts to meet the research goals and objectives of this extensive undertaking. (authors)

Graphical-based construction of combinatorial geometries for radiation transport and shielding applications

International Nuclear Information System (INIS)

Burns, T.J.

1992-01-01

A graphical-based code system is being developed at ORNL to manipulate combinatorial geometries for radiation transport and shielding applications. The current version (basically a combinatorial geometry debugger) consists of two parts: a FORTRAN-based ''view'' generator and a Microsoft Windows application for displaying the geometry. Options and features of both modules are discussed. Examples illustrating the various options available are presented. The potential for utilizing the images produced using the debugger as a visualization tool for the output of the radiation transport codes is discussed as is the future direction of the development

RADHEAT-V4: a code system to generate multigroup constants and analyze radiation transport for shielding safety evaluation

International Nuclear Information System (INIS)

Yamano, Naoki; Minami, Kazuyoshi; Koyama, Kinji; Naito, Yoshitaka.

1989-03-01

A modular code system RADHEAT-V4 has been developed for performing precisely neutron and photon transport analyses, and shielding safety evaluations. The system consists of the functional modules for producing coupled multi-group neutron and photon cross section sets, for analyzing the neutron and photon transport, and for calculating the atom displacement and the energy deposition due to radiations in nuclear reactor or shielding material. A precise method named Direct Angular Representation (DAR) has been developed for eliminating an error associated with the method of the finite Legendre expansion in evaluating angular distributions of cross sections and radiation fluxes. The DAR method implemented in the code system has been described in detail. To evaluate the accuracy and applicability of the code system, some test calculations on strong anisotropy problems have been performed. From the results, it has been concluded that RADHEAT-V4 is successfully applicable to evaluating shielding problems accurately for fission and fusion reactors and radiation sources. The method employed in the code system is very effective in eliminating negative values and oscillations of angular fluxes in a medium having an anisotropic source or strong streaming. Definitions of the input data required in various options of the code system and the sample problems are also presented. (author)

Safety demonstration analyses for severe accident of fresh nuclear fuel transport packages at JAERI

International Nuclear Information System (INIS)

Yamada, K.; Watanabe, K.; Nomura, Y.; Okuno, H.; Miyoshi, Y.

2004-01-01

It is expected in the near future that more and more fresh nuclear fuel will be transported in a variety of transport packages to cope with increasing demand from nuclear fuel cycle facilities. Accordingly, safety demonstration analyses of these methods are planned and conducted at JAERI under contract with the Ministry of Economy, Trade and Industry of Japan. These analyses are conducted part of a four year plan from 2001 to 2004 to verify integrity of packaging against leakage of radioactive material in the case of a severe accident envisioned to occur during transportation, for the purpose of gaining public acceptance of such nuclear fuel activities. In order to create the accident scenarios, actual transportation routes were surveyed, accident or incident records were tracked, international radioactive material transport regulations such as IAEA rules were investigated and, thus, accident conditions leading to mechanical damage and thermal failure were selected for inclusion in the scenario. As a result, the worst-case conditions of run-off-the-road accidents were incorporated, where there is impact against a concrete or asphalt surface. Fire accidents were assumed to occur after collision with a tank truck carrying lots of inflammable material or destruction by fire after collision inside a tunnel. The impact analyses were performed by using three-dimensional elements according to the general purpose impact analysis code LS-DYNA. Leak-tightness of the package was maintained even in the severe impact accident scenario. In addition, the thermal analyses were performed by using two-dimensional elements according to the general purpose finite element method computer code ABAQUS. As a result of these analyses, the integrity of the inside packaging component was found to be sufficient to maintain a leak-tight state, confirming its safety

Atmospheric transport, clouds and the Arctic longwave radiation paradox

Science.gov (United States)

Sedlar, Joseph

2016-04-01

Clouds interact with radiation, causing variations in the amount of electromagnetic energy reaching the Earth's surface, or escaping the climate system to space. While globally clouds lead to an overall cooling radiative effect at the surface, over the Arctic, where annual cloud fractions are high, the surface cloud radiative effect generally results in a warming. The additional energy input from absorption and re-emission of longwave radiation by the clouds to the surface can have a profound effect on the sea ice state. Anomalous atmospheric transport of heat and moisture into the Arctic, promoting cloud formation and enhancing surface longwave radiation anomalies, has been identified as an important mechanism in preconditioning Arctic sea ice for melt. Longwave radiation is emitted equally in all directions, and changes in the atmospheric infrared emission temperature and emissivity associated with advection of heat and moisture over the Arctic should correspondingly lead to an anomalous signal in longwave radiation at the top of the atmosphere (TOA). To examine the role of atmospheric heat and moisture transport into the Arctic on TOA longwave radiation, infrared satellite sounder observations from AIRS during 2003-2014 are analyzed for summer (JJAS). Thermodynamic metrics are developed to identify months characterized by a high frequency of warm and moist advection into the Arctic, and segregate the 2003-14 time period into climatological and anomalously warm, moist summer months. We find that anomalously warm, moist months result in a significant TOA longwave radiative cooling, which is opposite the forcing signal that the surface experiences during these months. At the timescale of the advective events, 3-10 days, the TOA cooling can be as large as the net surface energy budget during summer. When averaged on the monthly time scale, and over the full Arctic basin (poleward of 75°N), summer months experiencing frequent warm, moist advection events are

Premar-2: a Monte Carlo code for radiative transport simulation in atmospheric environments

International Nuclear Information System (INIS)

Cupini, E.

1999-01-01

The peculiarities of the PREMAR-2 code, aimed at radiation transport Monte Carlo simulation in atmospheric environments in the infrared-ultraviolet frequency range, are described. With respect to the previously developed PREMAR code, besides plane multilayers, spherical multilayers and finite sequences of vertical layers, each one with its own atmospheric behaviour, are foreseen in the new code, together with the refraction phenomenon, so that long range, highly slanted paths can now be more faithfully taken into account. A zenithal angular dependence of the albedo coefficient has moreover been introduced. Lidar systems, with spatially independent source and telescope, are allowed again to be simulated, and, in this latest version of the code, sensitivity analyses to be performed. According to this last feasibility, consequences on radiation transport of small perturbations in physical components of the atmospheric environment may be analyze and the related effects on searched results estimated. The availability of a library of physical data (reaction coefficients, phase functions and refraction indexes) is required by the code, providing the essential features of the environment of interest needed of the Monte Carlo simulation. Variance reducing techniques have been enhanced in the Premar-2 code, by introducing, for instance, a local forced collision technique, especially apt to be used in Lidar system simulations. Encouraging comparisons between code and experimental results carried out at the Brasimone Centre of ENEA, have so far been obtained, even if further checks of the code are to be performed [it

The effect on radiation damage of structural material in a hybrid system by using a Monte Carlo radiation transport code

International Nuclear Information System (INIS)

Günay, Mehtap; Şarer, Başar; Kasap, Hızır

2014-01-01

Highlights: • The effects of some fluids on gas production rates in structural material were investigated. • The MCNPX-2.7.0 Monte Carlo code was used for three-dimensional calculations. • It was found that biggest contribution to gas production rates comes from Fe isotope of the. • The desirable values for 5% SFG-PuO 2 with respect to radiation damage were specified. - Abstract: In this study, the molten salt-heavy metal mixtures 99–95% Li20Sn80-1-5% SFG-Pu, 99–95% Li20Sn80-1-5% SFG-PuF4, 99-95% Li20Sn80-1-5% SFG-PuO2 were used as fluids. The fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. 9Cr2WVTa ferritic steel with the width of 4 cm was used as the structural material. The parameters of radiation damage are proton, deuterium, tritium, He-3 and He-4 gas production rates. In this study, the effects of the selected fluid on the radiation damage, in terms of individual as well as total isotopes in the structural material, were investigated for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent version of the MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library

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.

Application of radiation protection programmes to transport of radioactive material

International Nuclear Information System (INIS)

Lopez Vietri, Jorge; Capadona, Nancy; Barenghi, Leonardo

2008-01-01

Full text: The principles for implementing radiation protection programmes (RPP) are detailed in the draft IAEA safety guide TS-G-1.5 'Radiation protection programmes for transport of radioactive material'. The document is described in this paper and analysis is made for typical applications to current operations carried out by consignors, carriers and consignees. Systematic establishment and application of RPPs is a way to control radiological protection during different steps of transport activity. The most widely transported packages in the world are radiopharmaceuticals by road. It is described an application of RPP for an organization involved in road transport of Type A packages containing radiopharmaceuticals. Considerations based on the radionuclides, quantities and activities transported are the basis to design and establish the scope of the RPP for the organizations involved in transport. Next stage is the determination of roles and responsibilities for each activity related to transport of radioactive materials. An approach to the dose received by workers is evaluated considering the type, category and quantity of packages, the radionuclides, the frequency of consignments and how long are the storages. The average of transports made in the last years must be taken into account and special measures intended to optimize the protection are evaluated. Tasks like monitoring, control of surface contamination and segregation measures, are designed based on the dose evaluation and optimization. The RPP also indicates main measures to follow in case of emergency during transport taking account of radionuclides, activities and category of packages for different accident scenarios. Basis for training personnel involved in handling of radioactive materials to insure they have appropriate knowledge about preparing packages, measuring dose rates, calculating transport index, labelling, marking and placarding, transport documents, etc, are considered. The RPP is a part

Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

Energy Technology Data Exchange (ETDEWEB)

Smedley-Stevenson, Richard P., E-mail: richard.smedley-stevenson@awe.co.uk [AWE PLC, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Department of Earth Science and Engineering, Imperial College London, SW7 2AZ (United Kingdom); McClarren, Ryan G., E-mail: rmcclarren@ne.tamu.edu [Department of Nuclear Engineering, Texas A & M University, College Station, TX 77843-3133 (United States)

2015-04-01

This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as ‘source tilting’. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange–Eulerian) hydrodynamics schemes.

Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

International Nuclear Information System (INIS)

Smedley-Stevenson, Richard P.; McClarren, Ryan G.

2015-01-01

This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as ‘source tilting’. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange–Eulerian) hydrodynamics schemes

Anthology of the Development of Radiation Transport Tools as Applied to Single Event Effects

Science.gov (United States)

Reed, R. A.; Weller, R. A.; Akkerman, A.; Barak, J.; Culpepper, W.; Duzellier, S.; Foster, C.; Gaillardin, M.; Hubert, G.; Jordan, T.; Jun, I.; Koontz, S.; Lei, F.; McNulty, P.; Mendenhall, M. H.; Murat, M.; Nieminen, P.; O'Neill, P.; Raine, M.; Reddell, B.; Saigné, F.; Santin, G.; Sihver, L.; Tang, H. H. K.; Truscott, P. R.; Wrobel, F.

2013-06-01

This anthology contains contributions from eleven different groups, each developing and/or applying Monte Carlo-based radiation transport tools to simulate a variety of effects that result from energy transferred to a semiconductor material by a single particle event. The topics span from basic mechanisms for single-particle induced failures to applied tasks like developing websites to predict on-orbit single event failure rates using Monte Carlo radiation transport tools.

Boundary and interface conditions for polarized radiation transport in a multilayer medium

International Nuclear Information System (INIS)

Garcia, R.D.M.

2011-01-01

In many applications of radiation transport, it is important to consider the changes in the index of refraction that occur when the physical domain being studied consists of material regions with distinct electromagnetic properties. When polarization effects are taken into account, the radiation eld is characterized by a vector of four components known as Stokes vector. At an interface between two different material regions, the reflected and transmitted Stokes vectors are related to the incident Stokes vector by means of reflection and transmission matrices, which are derived from the Fresnel formulas for the amplitude coefficients of reflection and transmission. Having seen that most works on polarized radiation transport that allow for changes in the index of refraction exhibit discrepancies in their expressions for the transmission matrix, we present in this work a careful derivation of the relations between the reflected and transmitted Stokes vectors and the Stokes vector incident on an interface. We obtain a general form of a transmission factor that is required to ensure conservation of energy and we show that most of the discrepancies encountered in existing works are due to the use of improper forms of this factor. In addition, we derive explicit and compact expressions for the Fresnel boundary and interface conditions appropriate to the study of polarized radiation transport in a multilayer medium. (author)

AREVA Developments for an Efficient and Reliable use of Monte Carlo codes for Radiation Transport Applications

Directory of Open Access Journals (Sweden)

Chapoutier Nicolas

2017-01-01

Full Text Available In the context of the rising of Monte Carlo transport calculations for any kind of application, AREVA recently improved its suite of engineering tools in order to produce efficient Monte Carlo workflow. Monte Carlo codes, such as MCNP or TRIPOLI, are recognized as reference codes to deal with a large range of radiation transport problems. However the inherent drawbacks of theses codes - laboring input file creation and long computation time - contrast with the maturity of the treatment of the physical phenomena. The goals of the recent AREVA developments were to reach similar efficiency as other mature engineering sciences such as finite elements analyses (e.g. structural or fluid dynamics. Among the main objectives, the creation of a graphical user interface offering CAD tools for geometry creation and other graphical features dedicated to the radiation field (source definition, tally definition has been reached. The computations times are drastically reduced compared to few years ago thanks to the use of massive parallel runs, and above all, the implementation of hybrid variance reduction technics. From now engineering teams are capable to deliver much more prompt support to any nuclear projects dealing with reactors or fuel cycle facilities from conceptual phase to decommissioning.

Non-classical radiation transport in random media with fluctuating densities

International Nuclear Information System (INIS)

Dyuldya, S.V.; Bratchenko, M.I.

2012-01-01

The ensemble averaged propagation kernels of the non-classical radiation transport are studied by means of the proposed application of the stochastic differential equation random medium generators. It is shown that the non-classical transport is favored in long-correlated weakly fluctuating media. The developed kernel models have been implemented in GEANT4 and validated against the d ouble Monte Carlo m odeling of absorptions curves of disperse neutron absorbers and γ-albedos from a scatterer/absorber random mix

Applications Of Monte Carlo Radiation Transport Simulation Techniques For Predicting Single Event Effects In Microelectronics

International Nuclear Information System (INIS)

Warren, Kevin; Reed, Robert; Weller, Robert; Mendenhall, Marcus; Sierawski, Brian; Schrimpf, Ronald

2011-01-01

MRED (Monte Carlo Radiative Energy Deposition) is Vanderbilt University's Geant4 application for simulating radiation events in semiconductors. Geant4 is comprised of the best available computational physics models for the transport of radiation through matter. In addition to basic radiation transport physics contained in the Geant4 core, MRED has the capability to track energy loss in tetrahedral geometric objects, includes a cross section biasing and track weighting technique for variance reduction, and additional features relevant to semiconductor device applications. The crucial element of predicting Single Event Upset (SEU) parameters using radiation transport software is the creation of a dosimetry model that accurately approximates the net collected charge at transistor contacts as a function of deposited energy. The dosimetry technique described here is the multiple sensitive volume (MSV) model. It is shown to be a reasonable approximation of the charge collection process and its parameters can be calibrated to experimental measurements of SEU cross sections. The MSV model, within the framework of MRED, is examined for heavy ion and high-energy proton SEU measurements of a static random access memory.

Anthology of the development of radiation transport tools as applied to single event effects

International Nuclear Information System (INIS)

Akkerman, A.; Barak, J.; Murat, M.; Duzellier, S.; Hubert, G.; Gaillardin, M.; Raine, M.; Jordan, T.; Jun, I.; Koontz, S.; Reddell, B.; O'Neill, P.; Foster, C.; Culpepper, W.; Lei, F.; McNulty, P.; Nieminen, P.; Saigne, F.; Wrobel, F.; Santin, G.; Sihver, L.; Tang, H.H.K.; Truscott, P.R.

2013-01-01

This anthology contains contributions from eleven different groups, each developing and/or applying Monte Carlo-based radiation transport tools to simulate a variety of effects that result from energy transferred to a semiconductor material by a single particle event. The topics span from basic mechanisms for single-particle induced failures to applied tasks like developing web sites to predict on-orbit single event failure rates using Monte Carlo radiation transport tools. (authors)

Finite element approximation of the radiative transport equation in a medium with piece-wise constant refractive index

International Nuclear Information System (INIS)

Lehtikangas, O.; Tarvainen, T.; Kim, A.D.; Arridge, S.R.

2015-01-01

The radiative transport equation can be used as a light transport model in a medium with scattering particles, such as biological tissues. In the radiative transport equation, the refractive index is assumed to be constant within the medium. However, in biomedical media, changes in the refractive index can occur between different tissue types. In this work, light propagation in a medium with piece-wise constant refractive index is considered. Light propagation in each sub-domain with a constant refractive index is modeled using the radiative transport equation and the equations are coupled using boundary conditions describing Fresnel reflection and refraction phenomena on the interfaces between the sub-domains. The resulting coupled system of radiative transport equations is numerically solved using a finite element method. The approach is tested with simulations. The results show that this coupled system describes light propagation accurately through comparison with the Monte Carlo method. It is also shown that neglecting the internal changes of the refractive index can lead to erroneous boundary measurements of scattered light

On the Momentum Transported by the Radiation Field of a Long Transient Dipole and Time Energy Uncertainty Principle

Directory of Open Access Journals (Sweden)

Vernon Cooray

2016-11-01

Full Text Available The paper describes the net momentum transported by the transient electromagnetic radiation field of a long transient dipole in free space. In the dipole a current is initiated at one end and propagates towards the other end where it is absorbed. The results show that the net momentum transported by the radiation is directed along the axis of the dipole where the currents are propagating. In general, the net momentum P transported by the electromagnetic radiation of the dipole is less than the quantity U / c , where U is the total energy radiated by the dipole and c is the speed of light in free space. In the case of a Hertzian dipole, the net momentum transported by the radiation field is zero because of the spatial symmetry of the radiation field. As the effective wavelength of the current decreases with respect to the length of the dipole (or the duration of the current decreases with respect to the travel time of the current along the dipole, the net momentum transported by the radiation field becomes closer and closer to U / c , and for effective wavelengths which are much shorter than the length of the dipole, P ≈ U / c . The results show that when the condition P ≈ U / c is satisfied, the radiated fields satisfy the condition Δ t Δ U ≥ h / 4 π where Δ t is the duration of the radiation, Δ U is the uncertainty in the dissipated energy and h is the Plank constant.

Toolkit for high performance Monte Carlo radiation transport and activation calculations for shielding applications in ITER

International Nuclear Information System (INIS)

Serikov, A.; Fischer, U.; Grosse, D.; Leichtle, D.; Majerle, M.

2011-01-01

The Monte Carlo (MC) method is the most suitable computational technique of radiation transport for shielding applications in fusion neutronics. This paper is intended for sharing the results of long term experience of the fusion neutronics group at Karlsruhe Institute of Technology (KIT) in radiation shielding calculations with the MCNP5 code for the ITER fusion reactor with emphasizing on the use of several ITER project-driven computer programs developed at KIT. Two of them, McCad and R2S, seem to be the most useful in radiation shielding analyses. The McCad computer graphical tool allows to perform automatic conversion of the MCNP models from the underlying CAD (CATIA) data files, while the R2S activation interface couples the MCNP radiation transport with the FISPACT activation allowing to estimate nuclear responses such as dose rate and nuclear heating after the ITER reactor shutdown. The cell-based R2S scheme was applied in shutdown photon dose analysis for the designing of the In-Vessel Viewing System (IVVS) and the Glow Discharge Cleaning (GDC) unit in ITER. Newly developed at KIT mesh-based R2S feature was successfully tested on the shutdown dose rate calculations for the upper port in the Neutral Beam (NB) cell of ITER. The merits of McCad graphical program were broadly acknowledged by the neutronic analysts and its continuous improvement at KIT has introduced its stable and more convenient run with its Graphical User Interface. Detailed 3D ITER neutronic modeling with the MCNP Monte Carlo method requires a lot of computation resources, inevitably leading to parallel calculations on clusters. Performance assessments of the MCNP5 parallel runs on the JUROPA/HPC-FF supercomputer cluster permitted to find the optimal number of processors for ITER-type runs. (author)

Changing transport processes in the stratosphere by radiative heating of sulfate aerosols

Directory of Open Access Journals (Sweden)

U. Niemeier

2017-12-01

Full Text Available The injection of sulfur dioxide (SO2 into the stratosphere to form an artificial stratospheric aerosol layer is discussed as an option for solar radiation management. Sulfate aerosol scatters solar radiation and absorbs infrared radiation, which warms the stratospheric sulfur layer. Simulations with the general circulation model ECHAM5-HAM, including aerosol microphysics, show consequences of this warming, including changes of the quasi-biennial oscillation (QBO in the tropics. The QBO slows down after an injection of 4 Tg(S yr−1 and completely shuts down after an injection of 8 Tg(S yr−1. Transport of species in the tropics and sub-tropics depends on the phase of the QBO. Consequently, the heated aerosol layer not only impacts the oscillation of the QBO but also the meridional transport of the sulfate aerosols. The stronger the injection, the stronger the heating and the simulated impact on the QBO and equatorial wind systems. With increasing injection rate the velocity of the equatorial jet streams increases, and the less sulfate is transported out of the tropics. This reduces the global distribution of sulfate and decreases the radiative forcing efficiency of the aerosol layer by 10 to 14 % compared to simulations with low vertical resolution and without generated QBO. Increasing the height of the injection increases the radiative forcing only for injection rates below 10 Tg(S yr−1 (8–18 %, a much smaller value than the 50 % calculated previously. Stronger injection rates at higher levels even result in smaller forcing than the injections at lower levels.

Integrated Radiation Transport and Nuclear Fuel Performance for Assembly-Level Simulations

Energy Technology Data Exchange (ETDEWEB)

Clarno, Kevin T [ORNL; Hamilton, Steven P [ORNL; Philip, Bobby [ORNL; Berrill, Mark A [ORNL; Sampath, Rahul S [ORNL; Allu, Srikanth [ORNL; Pugmire, Dave [ORNL; Dilts, Gary [Los Alamos National Laboratory (LANL); Banfield, James E [ORNL

2012-02-01

The Advanced Multi-Physics (AMP) Nuclear Fuel Performance code (AMPFuel) is focused on predicting the temperature and strain within a nuclear fuel assembly to evaluate the performance and safety of existing and advanced nuclear fuel bundles within existing and advanced nuclear reactors. AMPFuel was extended to include an integrated nuclear fuel assembly capability for (one-way) coupled radiation transport and nuclear fuel assembly thermo-mechanics. This capability is the initial step toward incorporating an improved predictive nuclear fuel assembly modeling capability to accurately account for source-terms and boundary conditions of traditional (single-pin) nuclear fuel performance simulation, such as the neutron flux distribution, coolant conditions, and assembly mechanical stresses. A novel scheme is introduced for transferring the power distribution from the Scale/Denovo (Denovo) radiation transport code (structured, Cartesian mesh with smeared materials within each cell) to AMPFuel (unstructured, hexagonal mesh with a single material within each cell), allowing the use of a relatively coarse spatial mesh (10 million elements) for the radiation transport and a fine spatial mesh (3.3 billion elements) for thermo-mechanics with very little loss of accuracy. In addition, a new nuclear fuel-specific preconditioner was developed to account for the high aspect ratio of each fuel pin (12 feet axially, but 1 4 inches in diameter) with many individual fuel regions (pellets). With this novel capability, AMPFuel was used to model an entire 17 17 pressurized water reactor fuel assembly with many of the features resolved in three dimensions (for thermo-mechanics and/or neutronics), including the fuel, gap, and cladding of each of the 264 fuel pins; the 25 guide tubes; the top and bottom structural regions; and the upper and lower (neutron) reflector regions. The final, full assembly calculation was executed on Jaguar using 40,000 cores in under 10 hours to model over 162

Analyses of the transportation of spent research reactor fuel in the United States

International Nuclear Information System (INIS)

Cashwell, J.W.; Neuhauser, K.S.

1989-01-01

The Transportation Technology Center at Sandia National Laboratories has analyzed the impacts of transportation of research reactor spent fuel from US and foreign reactors for the US Department of Energy (DOE) Office of Defense Programs. This effort represents the first comprehensive analytical evaluation of the risks of transporting high-, medium-, and low-enriched uranium spent research reactor fuel by both sea and land. Two separate shipment programs have been analyzed: the shipment of research reactor spent fuel from Taiwan to the US (Fuel Movement Program), and the return of research reactor spent fuels of US origin from foreign and domestic reactors (Research Reactor Fuel Return Program). In order to perform these analyses, a comprehensive methodology for analyzing the probabilities and consequences of transportation in coastal waters and port facilities, handling at the port, and shipment by truck to reprocessing facilities was developed. The Taiwanese fuel consists of low-burnup aluminum-clad metallic uranium research reactor spent fuel; the other fuels are primarily aluminum-clad oxide fuels. The Fuel Movement Program is ongoing, while the Fuel Return Program addresses future shipments over a ten-year period. The operational aspects of the Taiwanese shipments have been uniform, but several possible shipping configurations are possible for the Fuel Return Program shipments. Comprehensive assessments, which bound the impacts of spent fuel transport, demonstrate that when shipments are made in compliance with applicable regulations, the risks for all such transport are low. For comparison with previously licensed transport activities and to provide continuity with earlier analyses, the results for shipment of 150-day-old commercial pressurized water reactor (PWR) spent fuel are presented as part of this study

Rare Event Simulation in Radiation Transport

Science.gov (United States)

Kollman, Craig

This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved, even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiplied by the likelihood ratio between the true and simulated probabilities so as to keep our estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive "learning" algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give, with probability one, a sequence of estimates converging exponentially fast to the true solution. In the final chapter, an attempt to generalize this algorithm to a continuous

Monte Carlo closure for moment-based transport schemes in general relativistic radiation hydrodynamic simulations

Science.gov (United States)

Foucart, Francois

2018-04-01

General relativistic radiation hydrodynamic simulations are necessary to accurately model a number of astrophysical systems involving black holes and neutron stars. Photon transport plays a crucial role in radiatively dominated accretion discs, while neutrino transport is critical to core-collapse supernovae and to the modelling of electromagnetic transients and nucleosynthesis in neutron star mergers. However, evolving the full Boltzmann equations of radiative transport is extremely expensive. Here, we describe the implementation in the general relativistic SPEC code of a cheaper radiation hydrodynamic method that theoretically converges to a solution of Boltzmann's equation in the limit of infinite numerical resources. The algorithm is based on a grey two-moment scheme, in which we evolve the energy density and momentum density of the radiation. Two-moment schemes require a closure that fills in missing information about the energy spectrum and higher order moments of the radiation. Instead of the approximate analytical closure currently used in core-collapse and merger simulations, we complement the two-moment scheme with a low-accuracy Monte Carlo evolution. The Monte Carlo results can provide any or all of the missing information in the evolution of the moments, as desired by the user. As a first test of our methods, we study a set of idealized problems demonstrating that our algorithm performs significantly better than existing analytical closures. We also discuss the current limitations of our method, in particular open questions regarding the stability of the fully coupled scheme.

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 4, August 2014

International Nuclear Information System (INIS)

2014-08-01

IAEA’s Division of Radiation, Transport and Waste Safety is assisting Member States to develop national strategies for education and training in radiation, transport and waste safety via the regional projects on “Strengthening Education and Training Infrastructure, and Building Competence in Radiation Safety” (RAF/9/04, RAS/9/066, RER/9/109 and RLA/9/070). The regional workshops conducted in 2012 in this area and the results achieved were presented in the previous issues of this newsletter focussing specifically on each region of the Technical Cooperation Programme (Africa, Asia and the Pacific, Europe and Latin America). In the course of 2013, a new cycle of Regional Workshops was conducted. The workshops held in the regions of Africa, Asia and the Pacific, and Europe mainly focussed on Sharing Experience and Progress made in establishing a National Strategy for Education and Training in Radiation, Transport and Waste Safety (pages 2-5). The workshop held in the region of Latin America mainly focussed on Developing and Implementing Education and Training programmes. An overview on the results achieved by participating Member States for the period 2012-2013 is provided

Compendium of Material Composition Data for Radiation Transport Modeling

Energy Technology Data Exchange (ETDEWEB)

McConn, Ronald J.; Gesh, Christopher J.; Pagh, Richard T.; Rucker, Robert A.; Williams III, Robert

2011-03-04

Introduction Meaningful simulations of radiation transport applications require realistic definitions of material composition and densities. When seeking that information for applications in fields such as homeland security, radiation shielding and protection, and criticality safety, researchers usually encounter a variety of materials for which elemental compositions are not readily available or densities are not defined. Publication of the Compendium of Material Composition Data for Radiation Transport Modeling, Revision 0, in 2006 was the first step toward mitigating this problem. Revision 0 of this document listed 121 materials, selected mostly from the combined personal libraries of staff at the Pacific Northwest National Laboratory (PNNL), and thus had a scope that was recognized at the time to be limited. Nevertheless, its creation did provide a well-referenced source of some unique or hard-to-define material data in a format that could be used directly in radiation transport calculations being performed at PNNL. Moreover, having a single common set of material definitions also helped to standardize at least one aspect of the various modeling efforts across the laboratory by providing separate researchers the ability to compare different model results using a common basis of materials. The authors of the 2006 compendium understood that, depending on its use and feedback, the compendium would need to be revised to correct errors or inconsistencies in the data for the original 121 materials, as well as to increase (per users suggestions) the number of materials listed. This 2010 revision of the compendium has accomplished both of those objectives. The most obvious change is the increased number of materials from 121 to 372. The not-so-obvious change is the mechanism used to produce the data listed here. The data listed in the 2006 document were compiled, evaluated, entered, and error-checked by a group of individuals essentially by hand, providing no library

Computer codes in nuclear safety, radiation transport and dosimetry

International Nuclear Information System (INIS)

Bordy, J.M.; Kodeli, I.; Menard, St.; Bouchet, J.L.; Renard, F.; Martin, E.; Blazy, L.; Voros, S.; Bochud, F.; Laedermann, J.P.; Beaugelin, K.; Makovicka, L.; Quiot, A.; Vermeersch, F.; Roche, H.; Perrin, M.C.; Laye, F.; Bardies, M.; Struelens, L.; Vanhavere, F.; Gschwind, R.; Fernandez, F.; Quesne, B.; Fritsch, P.; Lamart, St.; Crovisier, Ph.; Leservot, A.; Antoni, R.; Huet, Ch.; Thiam, Ch.; Donadille, L.; Monfort, M.; Diop, Ch.; Ricard, M.

2006-01-01

The purpose of this conference was to describe the present state of computer codes dedicated to radiation transport or radiation source assessment or dosimetry. The presentations have been parted into 2 sessions: 1) methodology and 2) uses in industrial or medical or research domains. It appears that 2 different calculation strategies are prevailing, both are based on preliminary Monte-Carlo calculations with data storage. First, quick simulations made from a database of particle histories built though a previous Monte-Carlo simulation and secondly, a neuronal approach involving a learning platform generated through a previous Monte-Carlo simulation. This document gathers the slides of the presentations

Radiation Transport Around Axisymmetric Blunt Body Vehicles Using a Modified Differential Approximation

Science.gov (United States)

Hartung, Lin C.; Hassan, H. A.

1992-01-01

A moment method for computing 3-D radiative transport is applied to axisymmetric flows in thermochemical nonequilibrium. Such flows are representative of proposed aerobrake missions. The method uses the P-1 approximation to reduce the governing system of integro-di erential equations to a coupled set of partial di erential equations. A numerical solution method for these equations given actual variations of the radiation properties in thermochemical nonequilibrium blunt body flows is developed. Initial results from the method are shown and compared to tangent slab calculations. The agreement between the transport methods is found to be about 10 percent in the stagnation region, with the difference increasing along the flank of the vehicle.

Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Moore, A. S., E-mail: alastair.moore@physics.org; Graham, P.; Comley, A. J.; Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading RG7 4PR (United Kingdom); Cooper, A. B. R.; Schneider, M. B.; MacLaren, S.; Lu, K.; Seugling, R.; Satcher, J.; Klingmann, J.; Marrs, R.; May, M.; Widmann, K.; Glendinning, G.; Castor, J.; Sain, J.; Baker, K.; Hsing, W. W.; Young, B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2014-06-15

Experiments that characterize and develop a high energy-density half-hohlraum platform for use in benchmarking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240 eV. This creates a subsonic diffusive Marshak wave, which propagates into a high atomic number Ta{sub 2}O{sub 5} aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range of x-ray measurements that absolutely quantify the energetics and radiation partition inside the target.

Effects of radiation transport on mass ablation rate and conversion efficiency in numerical simulations of inertial confinement fusion

International Nuclear Information System (INIS)

Gupta, N.K.

2002-01-01

The effects of radiation transport on hydrodynamic parameters of laser produced plasmas are studied. LTE and non-LTE atomic models are used to calculate multi group opacities and emissivities. Screened hydrogenic atom model is used to calculate the energy levels. The population densities of neutral to fully ionized ions are obtained by solving the steady state rate equations. Radiation transport is treated in multi-group diffusion or Sn method. A comparison is made between 1 and 100 group radiation transport and LTE and non-LTE models. For aluminium, multi group radiation transport leads to much higher mass ablation as compared to the 1 group and no radiation transport cases. This in turn leads to higher ablation pressures. However, for gold gray approximation gives higher mass ablation as compared to multi group simulations. LTE conversion efficiency of laser light into x-rays is more than the non-LTE estimates. For LTE as well as non-LTE cases, the one group approximation over-predicts the conversion efficiency Multi group non-LTE simulations predict that the conversion efficiency increases with laser intensity up to a maximum and then it decreases. (author)

Transport of Terrestrial gamma-Radiation in Plane Semi-Infinite Geometry

DEFF Research Database (Denmark)

Kirkegaard, Peter; Løvborg, Leif

1980-01-01

The plane one-dimensional photon transport equation is solved for the scattered γ-radiation flux in the case of two adjacent media. One medium represents a natural ground with uniformly distributed potassium, uranium, and thorium γ-ray emitters. The other medium is air with no radioactive contami...

Analyses of the transportation of spent research reactor fuel in the United States

International Nuclear Information System (INIS)

Cashwell, J.W.; Neuhauser, K.S.

1989-01-01

We analyzed the impacts of transportation of research reactor spent fuel from US and foreign reactors for the US Department of Energy's (DOE) Office of Defense Programs. Two separate shipment programs were analyzed. The shipment of research reactor spent fuel from Taiwan to the US (Fuel Movement Program), and the return of research reactor spent fuels of US origin from foreign and domestic reactors (Research Reactor Fuel Return Program). To perform these analyses, a comprehensive methodology for analyzing the probabilities and consequences of transportation in coastal waters and port facilities, handling at the port, and shipment by truck to reprocessing facilities was developed. The Taiwanese fuel consists of low-burnup aluminum-clad metallic uranium research reactor spent fuel; the other fuels are primarily aluminum-clad oxide fuels. The Fuel Movement Program is ongoing, while the Fuel Return Program addresses future shipments over a ten-year period. The operational aspects of the Taiwanese shipments have been uniform, but several possible shipping configurations are possible for the Fuel Return Program shipments. The risks of transporting spent nuclear fuel and other radioactive materials by all modes have been analyzed extensively. Comprehensive assessments, which bound the impacts of spent fuel transport, demonstrate that when shipments are made in compliance with applicable regulations, the risks for all such transport are low. For comparison with previously licensed transport activities and to provide continuity with earlier analyses, the results for shipment of 150-day-old commercial pressurized water reactor (PWR) spent fuel are presented as part of this study

Treatment of spices with ionizing radiation - chemical, organoleptical, microbiological and toxicological analyses. Pt. 2

International Nuclear Information System (INIS)

Schuettler, C.; Boegl, W.

1984-09-01

In the present second part of a study of the relevant literature the results of tests on 14 radiation treated spices and 2 radiation treated spice-mixtures were evaluated. The tests in this part contain mainly toxicological but also chemical and sensorial analyses. Most of the spices were treated with gamma radiation from cobalt-60 sources with doses between 80 Gy and 60 kGy. This part contains a cumulated subject index for part 1 and part 2. (orig./AJ) [de

Atmospheric Ionizing Radiation and the High Speed Civil Transport. Chapter 1

Science.gov (United States)

Maiden, D. L.; Wilson, J. W.; Jones, I. W.; Goldhagen, P.

2003-01-01

Atmospheric ionizing radiation is produced by extraterrestrial radiations incident on the Earth's atmosphere. These extraterrestrial radiations are of two sources: ever present galactic cosmic rays with origin outside the solar system and transient solar particle events that are at times very intense events associated with solar activity lasting several hours to a few days. Although the galactic radiation penetrating through the atmosphere to the ground is low in intensity, the intensity is more than two orders of magnitude greater at commercial aircraft altitudes. The radiation levels at the higher altitudes of the High Speed Civil Transport (HSCT) are an additional factor of two higher. Ionizing radiation produces chemically active radicals in biological tissues that alter the cell function or result in cell death. Protection standards against low levels of ionizing radiation are based on limitation of excess cancer mortality or limitation of developmental injury resulting in permanent damage to the offspring during pregnancy. The crews of commercial air transport operations are considered as radiation workers by the EPA, the FAA, and the International Commission on Radiological Protection (ICRP). The annual exposures of aircrews depend on the latitudes and altitudes of operation and flight time. Flight hours have significantly increased since deregulation of the airline industry in the 1980's. The FAA estimates annual subsonic aircrew exposures to range from 0.2 to 9.1 mSv compared to 0.5 mSv exposure of the average nuclear power plant worker in the nuclear industry. The commercial aircrews of the HSCT may receive exposures above recently recommended allowable limits for even radiation workers if flying their allowable number of flight hours. An adequate protection philosophy for background exposures in HSCT commercial airtraffic cannot be developed at this time due to current uncertainty in environmental levels. In addition, if a large solar particle event

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)

Analysis of the energy efficiency of the transport system in Algeria; Analyse de l'efficacite energetique du systeme de transport en Algerie

Energy Technology Data Exchange (ETDEWEB)

Hamdani, Sid Ahmed

2010-09-15

The objective of this communication is analyze the energy efficiency of the transport system in Algeria and to show the areas of possible rationalization in this sector. Our approach is to analyze the existing configuration of the sector and its impact on energy consumption, by developing a sectional model Bottom Up, where the transport park has been modified by the means used. We have shown that the potential to improve the transport system energy efficiency is important and have recommended some options aimed at the sector organisation and aimed at increasing the relative part of transport systems to make it more energy efficient. [French] L'objectif de cette communication est d'analyser l'efficacite energetique du systeme de transport algerien et de montrer les gisements de rationalisation possibles dans ce secteur. Notre approche consiste a analyser la configuration existante du secteur et son impact sur la consommation d'energie, en elaborant un modele sectoriel Bottom Up, ou le parc de transport a ete desagrege par moyen utilise. Nous avons montre que le potentiel d'amelioration de la performance energetique du systeme de transport est important et avons recommande quelques options ciblant l'organisation du secteur et visant a augmenter la part relative de moyens de transport plus efficace energetiquement.

High-Fidelity Kinetics and Radiation Transport for NLTE Hypersonic Flows, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The modeling of NLTE hypersonic flows combines several disciplines: chemistry, kinetics, radiation transport, fluid mechanics, and surface science. No single code or...

Education and Training in Radiation, Transport and Waste Safety Newsletter, No. 3, May 2014

International Nuclear Information System (INIS)

2014-05-01

Building competence through education and training in radiation protection, radioactive waste safety, and safety in transport of radioactive material is fundamental to the establishment of a comprehensive and sustainable national infrastructure for radiation safety, which in turn is essential for the beneficial uses of radiation while ensuring appropriate protection of workers, patients, the public and the environment. IAEA’s Division of Radiation, Transport and Waste Safety provides direct assistance to Member States via a range of tools and mechanisms, such as by organizing educational and training events, developing standardized syllabi with supporting material and documents, and by fostering methodologies to build sustainable competence and enhance effectiveness in the provision of training. The main objective is to support Member States in the application of the IAEA Safety Standards. Seminars and additional activities are also promoted to broaden knowledge on relevant areas for an effective application of the standards

Vectorization and parallelization of Monte-Carlo programs for calculation of radiation transport

International Nuclear Information System (INIS)

Seidel, R.

1995-01-01

The versatile MCNP-3B Monte-Carlo code written in FORTRAN77, for simulation of the radiation transport of neutral particles, has been subjected to vectorization and parallelization of essential parts, without touching its versatility. Vectorization is not dependent on a specific computer. Several sample tasks have been selected in order to test the vectorized MCNP-3B code in comparison to the scalar MNCP-3B code. The samples are a representative example of the 3-D calculations to be performed for simulation of radiation transport in neutron and reactor physics. (1) 4πneutron detector. (2) High-energy calorimeter. (3) PROTEUS benchmark (conversion rates and neutron multiplication factors for the HCLWR (High Conversion Light Water Reactor)). (orig./HP) [de

Optical transport and statistics of radiative losses in disordered chains of microspheres

International Nuclear Information System (INIS)

Deng Chaosheng; Xu Hui; Deych, Lev

2010-01-01

Optical transport in a one-dimensional chain of microspherical resonators with size disorder is studied in the spectral range of high-Q whispering gallery modes. An ab initio approach is used to develop a theoretical framework for analysis of steady-state transport parameters with main emphasis on properly defined radiative loss coefficient. Probability distribution and scaling properties of the latter are established and explained.

Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

Science.gov (United States)

Zygmanski, Piotr; Sajo, Erno

2016-01-01

We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

Comparison of 2D and 3D Neutron Transport Analyses on Yonggwang Unit 3 Reactor

International Nuclear Information System (INIS)

Maeng, Aoung Jae; Kim, Byoung Chul; Lim, Mi Joung; Kim, Kyung Sik; Jeon, Young Kyou; Yoo, Choon Sung

2012-01-01

10 CFR Part 50 Appendix H requires periodical surveillance program in the reactor vessel (RV) belt line region of light water nuclear power plant to check vessel integrity resulting from the exposure to neutron irradiation and thermal environment. Exact exposure analysis of the neutron fluence based on right modeling and simulations is the most important in the evaluation. Traditional 2 dimensional (D) and 1D synthesis methodologies have been widely applied to evaluate the fast neutron (E > 1.0 MeV) fluence exposure to RV. However, 2D and 1D methodologies have not provided accurate fast neutron fluence evaluation at elevations far above or below the active core region. RAPTOR-M3G (RApid Parallel Transport Of Radiation - Multiple 3D Geometries) program for 3D geometries calculation was therefore developed both by Westinghouse Electronic Company, USA and Korea Reactor Integrity Surveillance Technology (KRIST) for the analysis of In-Vessel Surveillance Test and Ex-Vessel Neutron Dosimetry (EVND). Especially EVND which is installed at active core height between biological shielding material and concrete also evaluates axial neutron fluence by placing three dosimetries each at Top, Middle and Bottom part of the angle representing maximum neutron fluence. The EVND programs have been applied to the Korea Nuclear Plants. The objective of this study is therefore to compare the 3D and the 2D Neutron Transport Calculations and Analyses on the Yonggwang unit 3 Reactor as an example

Radiation transport phenomena and modeling. Part A: Codes; Part B: Applications with examples

International Nuclear Information System (INIS)

Lorence, L.J. Jr.; Beutler, D.E.

1997-09-01

This report contains the notes from the second session of the 1997 IEEE Nuclear and Space Radiation Effects Conference Short Course on Applying Computer Simulation Tools to Radiation Effects Problems. Part A discusses the physical phenomena modeled in radiation transport codes and various types of algorithmic implementations. Part B gives examples of how these codes can be used to design experiments whose results can be easily analyzed and describes how to calculate quantities of interest for electronic devices

Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport

International Nuclear Information System (INIS)

McKinley, M S; Brooks III, E D; Daffin, F

2004-01-01

Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the difference formulation for thermal photon transport, showing a significant advantage for Monte Carlo solution of the equations for time dependent transport. Other related areas are discussed that may also realize significant benefits from similar analytical transformations

Radiation transport modelling for the interpretation of oblique ECE measurements

Directory of Open Access Journals (Sweden)

Denk Severin S.

2017-01-01

Since radiation transport modelling is required for the interpretation of oblique ECE diagnostics we present in this paper an extended forward model that supports oblique lines of sight. To account for the refraction of the line of sight, ray tracing in the cold plasma approximation was added to the model. Furthermore, an absorption coefficient valid for arbitrary propagation was implemented. Using the revised model it is shown that for the oblique ECE Imaging diagnostic at ASDEX Upgrade there can be a significant difference between the cold resonance position and the point from which most of the observed radiation originates.

Recent developments in the Los Alamos radiation transport code system

International Nuclear Information System (INIS)

Forster, R.A.; Parsons, K.

1997-01-01

A brief progress report on updates to the Los Alamos Radiation Transport Code System (LARTCS) for solving criticality and fixed-source problems is provided. LARTCS integrates the Diffusion Accelerated Neutral Transport (DANT) discrete ordinates codes with the Monte Carlo N-Particle (MCNP) code. The LARCTS code is being developed with a graphical user interface for problem setup and analysis. Progress in the DANT system for criticality applications include a two-dimensional module which can be linked to a mesh-generation code and a faster iteration scheme. Updates to MCNP Version 4A allow statistical checks of calculated Monte Carlo results

Functional size of photosynthetic electron transport chain determined by radiation inactivation

International Nuclear Information System (INIS)

Pan, R.S.; Chen, L.F.; Wang, M.Y.; Tsal, M.Y.; Pan, R.L.; Hsu, B.D.

1987-01-01

Radiation inactivation technique was employed to determine the functional size of photosynthetic electron transport chain of spinach chloroplasts. The functional size for photosystem I+II(H 2 O to methylviologen) was 623 +/- 37 kilodaltons; for photosystem II (H 2 O to dimethylquinone/ferricyanide), 174 +/- 11 kilodaltons; and for photosystem I (reduced diaminodurene to methylviologen), 190 +/- 11 kilodaltons. The difference between 364 +/- 22 (the sum of 174 +/- 11 and 190 +/- 11) kilodaltons and 623 +/- 37 kilodaltons is partially explained to be due to the presence of two molecules of cytochrome b 6 /f complex of 280 kilodaltons. The molecular mass for other partial reactions of photosynthetic electron flow, also measured by radiation inactivation, is reported. The molecular mass obtained by this technique is compared with that determined by other conventional biochemical methods. A working hypothesis for the composition, stoichiometry, and organization of polypeptides for photosynthetic electron transport chain is proposed

F--Ray: A new algorithm for efficient transport of ionizing radiation

Science.gov (United States)

Mao, Yi; Zhang, J.; Wandelt, B. D.; Shapiro, P. R.; Iliev, I. T.

2014-04-01

We present a new algorithm for the 3D transport of ionizing radiation, called F2-Ray (Fast Fourier Ray-tracing method). The transfer of ionizing radiation with long mean free path in diffuse intergalactic gas poses a special challenge to standard numerical methods which transport the radiation in position space. Standard methods usually trace each individual ray until it is fully absorbed by the intervening gas. If the mean free path is long, the computational cost and memory load are likely to be prohibitive. We have developed an algorithm that overcomes these limitations and is, therefore, significantly more efficient. The method calculates the transfer of radiation collectively, using the Fast Fourier Transform to convert radiation between position and Fourier spaces, so the computational cost will not increase with the number of ionizing sources. The method also automatically combines parallel rays with the same frequency at the same grid cell, thereby minimizing the memory requirement. The method is explicitly photon-conserving, i.e. the depletion of ionizing photons is guaranteed to equal the photoionizations they caused, and explicitly obeys the periodic boundary condition, i.e. the escape of ionizing photons from one side of a simulation volume is guaranteed to be compensated by emitting the same amount of photons into the volume through the opposite side. Together, these features make it possible to numerically simulate the transfer of ionizing photons more efficiently than previous methods. Since ionizing radiation such as the X-ray is responsible for heating the intergalactic gas when first stars and quasars form at high redshifts, our method can be applied to simulate thermal distribution, in addition to cosmic reionization, in three-dimensional inhomogeneous cosmological density field.

Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Moore, A. S. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Cooper, A. B.R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacLaren, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Graham, P. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Lu, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seugling, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Satcher, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Klingmann, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Comley, A. J. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Marrs, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); May, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Widmann, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glendinning, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Castor, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sain, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Back, C. A. [General Atomics, San Diego, CA (United States); Hund, J. [General Atomics, San Diego, CA (United States); Baker, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hsing, W. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Young, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Young, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-06-01

Experiments that characterize and develop a high energy-density half-hohlraum platform for use in bench-marking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240 eV. This creates a subsonic di usive Marshak wave which propagates into a high atomic number Ta₂O₅ aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range

Site Specific Analyses of a Spent Nuclear Fuel Transportation Accident

International Nuclear Information System (INIS)

Biwer, B. M.; Chen, S. Y.

2003-01-01

The number of spent nuclear fuel (SNF) shipments is expected to increase significantly during the time period that the United States' inventory of SNF is sent to a final disposal site. Prior work estimated that the highest accident risks of a SNF shipping campaign to the proposed geologic repository at Yucca Mountain were in the corridor states, such as Illinois. The largest potential human health impacts would be expected to occur in areas with high population densities such as urban settings. Thus, our current study examined the human health impacts from the most plausible severe SNF transportation accidents in the Chicago metropolitan area. The RISKIND 2.0 program was used to model site-specific data for an area where the largest impacts might occur. The results have shown that the radiological human health consequences of a severe SNF rail transportation accident on average might be similar to one year of exposure to natural background radiation for those persons living a nd working in the most affected areas downwind of the actual accident location. For maximally exposed individuals, an exposure similar to about two years of exposure to natural background radiation was estimated. In addition to the accident probabilities being very low (approximately 1 chance in 10,000 or less during the entire shipping campaign), the actual human health impacts are expected to be lower if any of the accidents considered did occur, because the results are dependent on the specific location and weather conditions, such as wind speed and direction, that were selected to maximize the results. Also, comparison of the results of longer duration accident scenarios against U.S. Environmental Protection Agency guidelines was made to demonstrate the usefulness of this site-specific analysis for emergency planning purposes

Modeling radiative transport in ICF plasmas on an IBM SP2 supercomputer

International Nuclear Information System (INIS)

Johansen, J.A.; MacFarlane, J.J.; Moses, G.A.

1995-01-01

At the University of Wisconsin-Madison the authors have integrated a collisional-radiative-equilibrium model into their CONRAD radiation-hydrodynamics code. This integrated package allows them to accurately simulate the transport processes involved in ICF plasmas; including the important effects of self-absorption of line-radiation. However, as they increase the amount of atomic structure utilized in their transport models, the computational demands increase nonlinearly. In an attempt to meet this increased computational demand, they have recently embarked on a mission to parallelize the CONRAD program. The parallel CONRAD development is being performed on an IBM SP2 supercomputer. The parallelism is based on a message passing paradigm, and is being implemented using PVM. At the present time they have determined that approximately 70% of the sequential program can be executed in parallel. Accordingly, they expect that the parallel version will yield a speedup on the order of three times that of the sequential version. This translates into only 10 hours of execution time for the parallel version, whereas the sequential version required 30 hours

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

Safety demonstration analyses at JAERI for severe accident during overland transport of fresh nuclear fuel

International Nuclear Information System (INIS)

Nomura, Yasushi; Kitao, Kohichi; Karasawa, Kiyonori; Yamada, Kenji; Takahashi, Satoshi; Watanabe, Kohji; Okuno, Hiroshi; Miyoshi, Yoshinori

2005-01-01

It is expected in the near future that more and more fresh nuclear fuel will be transported in a variety of transport packages to cope with increasing demand from nuclear fuel cycle facilities. Accordingly, safety demonstration analyses are planned and conducted at JAERI under contract with the Ministry of Economy, Trade and Industry of Japan. These analyses are conducted in a four year plan from 2001 to 2004 to verify integrity of packaging against leakage of radioactive material in the case of a severe accident postulated to occur during transportation, for the purpose of gaining acceptance of such nuclear fuel activities. In order to create the accident scenarios, actual transportation routes were surveyed, accident or incident records were tracked, international radioactive material transport regulations such as IAEA rules were investigated and thus, accident conditions leading to mechanical damages and thermal failure were determined to characterize the scenarios. As a result, the worst-case conditions of run-off-the-road accidents were set up to define the impact against a concrete or asphalt surface. For fire accident scenarios to be set up, collisions were assumed to occur with an oil tanker carrying lots of inflammable material in open air, or with a commonly used two-ton-truck inside a tunnel without ventilation. Then the cask models were determined for these safety demonstration analyses to represent those commonly used for fresh nuclear fuel transported throughout Japan. Following the postulated accident scenarios, the mechanical damages were analyzed by using the general-purpose finite element code LS-DYNA with three-dimensional elements. It was found that leak tightness of the package be maintained even in the severe impact scenario. Then the thermal safety was analyzed by using the general-purpose finite element code ABAOUS with three-dimensional elements to describe cask geometry. As a result of the thermal analyses, the integrity of the containment

Flash spice as a tool for analysing the impact of radiation

International Nuclear Information System (INIS)

Charlot, J.J.; Alali, O.

1997-01-01

The Spice simulator must be enhanced with behavioural capabilities for analysing the effects of hostile environments (e.g. radiation exposure) on components, circuits and systems. One solution for achieving this uses the in-house BVHDLA translator to convert from models in analog VHDL Language to models that will be recognized by Spice. This article gives an example combined with self-heating in a MOS transistor. (authors)

Physiological and enzymatic analyses of pineapple subjected to ionizing radiation

International Nuclear Information System (INIS)

Silva, Josenilda Maria da; Silva, Juliana Pizarro; Spoto, Marta Helena Fillet

2007-01-01

The physiological and enzymatic post-harvest characteristics of the pineapple cultivar Smooth Cayenne were evaluated after the fruits were gamma-irradiated with doses of 100 and 150 Gy and the fruits were stored for 10, 20 and 30 days at 12 deg C (±1) and relative humidity of 85% (±5). Physiological and enzymatic analyses were made for each storage period to evaluate the alterations resulting from the application of ionizing radiation. Control specimens showed higher values of soluble pectins, total pectins, reducing sugars, sucrose and total sugars and lower values of polyphenyloxidase and polygalacturonase enzyme activities. All the analyses indicated that storage time is a significantly influencing factor. The 100 Gy dosage and 20-day storage period presented the best results from the standpoint of maturation and conservation of the fruits quality. (author)

grmonty: A MONTE CARLO CODE FOR RELATIVISTIC RADIATIVE TRANSPORT

International Nuclear Information System (INIS)

Dolence, Joshua C.; Gammie, Charles F.; Leung, Po Kin; Moscibrodzka, Monika

2009-01-01

We describe a Monte Carlo radiative transport code intended for calculating spectra of hot, optically thin plasmas in full general relativity. The version we describe here is designed to model hot accretion flows in the Kerr metric and therefore incorporates synchrotron emission and absorption, and Compton scattering. The code can be readily generalized, however, to account for other radiative processes and an arbitrary spacetime. We describe a suite of test problems, and demonstrate the expected N -1/2 convergence rate, where N is the number of Monte Carlo samples. Finally, we illustrate the capabilities of the code with a model calculation, a spectrum of the slowly accreting black hole Sgr A* based on data provided by a numerical general relativistic MHD model of the accreting plasma.

Experience with the loading and transport of fuel assembly transport casks, including CASTOR casks, and the radiation exposure of personnel

International Nuclear Information System (INIS)

Bentele, W.; Kinzelmann, T.

1999-01-01

In 1997 and 1998, six spent fuel assembly transports started from the nuclear power plant Gemeinschaftskernkraftwerk Neckar (GKN), using CASTOR-V19 casks. Professor Kuni of Marburg University challenged the statement made by the German Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz (BfS)) based on accepted scientific knowledge, according to which so-called CASTOR transports present no risk, either to the population or to the escorting police units. This paper shows that the collective dose during the loading of the CASTOR casks amounted to 4.5 mSv (gamma and neutrons) per cask at the most, and that the maximum individual dose amounted to 0.26 mSv. In addition to these doses, the collective dose during handling and transport must be considered: this amounted to 0.35 mSv (gamma and neutrons). The dose to the police escort was -2 (limit for surface contamination), presented degrees of contamination >4 Bq cm -2 upon reaching the Valognes/Cogema terminal. However, transport casks coming from French plants also revealed degrees of contamination >4 Bq cm -2 , as well as 'hot spots'. No such contamination was found on NTL 11 casks transported from the GKN to Sellafield. Neither was any increased contamination found upon the arrival of CASTOR-V19 casks transported from GKN to Gorleben or Ahaus. The partially sensationalist media reports were inversely proportional to the actual radiological relevance of the matter. The German Commission on Radiation Protection (SSK) confirmed that the radiological effect of such contaminated spent fuel transports is negligible. (author)

Simplified calculation method for radiation dose under normal condition of transport

International Nuclear Information System (INIS)

Watabe, N.; Ozaki, S.; Sato, K.; Sugahara, A.

1993-01-01

In order to estimate radiation dose during transportation of radioactive materials, the following computer codes are available: RADTRAN, INTERTRAN, J-TRAN. Because these codes consist of functions for estimating doses not only under normal conditions but also in the case of accidents, when nuclei may leak and spread into the environment by air diffusion, the user needs to have special knowledge and experience. In this presentation, we describe how, with a view to preparing a method by which a person in charge of transportation can calculate doses in normal conditions, the main parameters upon which the value of doses depends were extracted and the dose for a unit of transportation was estimated. (J.P.N.)

Radiation-induced dysfunction of colonic transport: role of enteric nervous system and of serotonine

International Nuclear Information System (INIS)

Francois, Agnes

1998-01-01

One of the most commonly observed features of radiation-induced injury of the gastrointestinal tract is the appearance of severe diarrhea. One difficulty in understanding the origin of radiation-induced diarrhea is the multiplicity of factors implicated, depending on the type of radiation, the dose received and the irradiated field. Colonic transport is regulated for a great part by the enteric nervous system (ENS), in close association with immunocompetent cells, especially mast cells. The aim of this study was to investigate whether the neuro-immune regulation of colonic transport could be implicated in radiation-induced attenuation and recovery of colonic functions. Male Wistar rats were whole-body irradiated at 3.8 Gy neutron or 5 and 10 Gy gamma. At 1 and 3 days after exposure, the colonic epithelium was hypo-responsive to neural stimulation (submucosal plexus). Mechanistic studies were performed after 10 Gy exposure. The decreased colonic transport was associated with the disappearance of both submucosal mast cells and histamine-mediated pathway, together with decreased responses to exogenous histamine. Similarly, the response to exogenous 5-HT was decreased, without any modification of either the neural (5-HT 3 ) or non-neural (5-HT 4 ) pathways. Seven days after exposure, colonic transport capacity returned to normal in spite of the absence of mast cells. However these observations were associated with the reappearance of a histaminergic pathway, the origin of which is still unknown. The part played by 5-HT 3 receptors was increased, together with the appearance of a neurally-associated 5-HT4 receptor-pathway. These results suggest that the decreased influence of the ENS on colonic transport observed 1 and 3 days after exposure may be due to both the disappearance of neuro-immune links and the hypo-responsiveness of colonic epithelium to the mediators released by ENS. The functional recovery at seven days may be related on one hand to the return of altered

Radiation shielding and criticality safety assessment for KN-12 spent nuclear fuel transport cask

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Kyung; Shin, Chang Ho; Kim, Gi Hwan [Hanyang Univ., Seoul (Korea, Republic of)

2001-08-15

Because SNFs involve TRU (Transuranium), fission products, and fissile materials, they are highly radioactive and also have a possibility to be critical. Therefore, radiation shielding and criticality safety for transport casks containing the SNFs should be guaranteed through reliable valuation procedure. IAEA safety standard series No ST-1 recommends regulation for safe transportation of the SNFs by transport casks, and United States is carrying out it according to the regulation guide, 10 CFR parts 71 and 72. Present research objective is to evaluate the KN-12 spent nuclear fuel transport cask that is designed for transportation of up to 12 assemblies and is standby status for being licensed in accordance with Korea Atomic Energy Act. Both radiation shielding and criticality analysis using the accurate Monte Carlo transport code, MCNP-4B are carried out for the KN-12 SNF cask as a benchmark calculation. Source terms for radiation shielding calculation are obtained using ORIGEN-S computer code. In this work, for normal transport conditions, the results from MCNP-4B shows the maximum dose rate of 0.557 mSv/hr at the side surface. And the maximum dose rate of 0.0871 mSv/hr was resulted at the 2 m distance from the cask. The level of calculated dose rate is 27.9% of the limit at the cask surface, 87.1% at 2 m from the cask surface for normal transport condition. For hypothetical accident conditions, the maximum rate of 2.5144 mSv/hr was resulted at the 1 m distance from the cask and this level is 25.1% of the limit for hypothetical accident conditions. In criticality calculations using MCNP-4B, the k{sub eff} values yielded for 5.0 w/o U-235 enriched fresh fuel are 0.92098 {+-} 0.00065. This result confirms subcritical condition of the KN-12 SNF cask and gives 96.95% of recommendations for criticality safety evaluation by US NRC these results will be useful as a basis for approval for the KN-12 SNF cask.

A Deterministic Electron, Photon, Proton and Heavy Ion Radiation Transport Suite for the Study of the Jovian System

Science.gov (United States)

Norman, Ryan B.; Badavi, Francis F.; Blattnig, Steve R.; Atwell, William

2011-01-01

A deterministic suite of radiation transport codes, developed at NASA Langley Research Center (LaRC), which describe the transport of electrons, photons, protons, and heavy ions in condensed media is used to simulate exposures from spectral distributions typical of electrons, protons and carbon-oxygen-sulfur (C-O-S) trapped heavy ions in the Jovian radiation environment. The particle transport suite consists of a coupled electron and photon deterministic transport algorithm (CEPTRN) and a coupled light particle and heavy ion deterministic transport algorithm (HZETRN). The primary purpose for the development of the transport suite is to provide a means for the spacecraft design community to rapidly perform numerous repetitive calculations essential for electron, proton and heavy ion radiation exposure assessments in complex space structures. In this paper, the radiation environment of the Galilean satellite Europa is used as a representative boundary condition to show the capabilities of the transport suite. While the transport suite can directly access the output electron spectra of the Jovian environment as generated by the Jet Propulsion Laboratory (JPL) Galileo Interim Radiation Electron (GIRE) model of 2003; for the sake of relevance to the upcoming Europa Jupiter System Mission (EJSM), the 105 days at Europa mission fluence energy spectra provided by JPL is used to produce the corresponding dose-depth curve in silicon behind an aluminum shield of 100 mils ( 0.7 g/sq cm). The transport suite can also accept ray-traced thickness files from a computer-aided design (CAD) package and calculate the total ionizing dose (TID) at a specific target point. In that regard, using a low-fidelity CAD model of the Galileo probe, the transport suite was verified by comparing with Monte Carlo (MC) simulations for orbits JOI--J35 of the Galileo extended mission (1996-2001). For the upcoming EJSM mission with a potential launch date of 2020, the transport suite is used to compute

Development and preliminary verification of 2-D transport module of radiation shielding code ARES

International Nuclear Information System (INIS)

Zhang Penghe; Chen Yixue; Zhang Bin; Zang Qiyong; Yuan Longjun; Chen Mengteng

2013-01-01

The 2-D transport module of radiation shielding code ARES is two-dimensional neutron and radiation shielding code. The theory model was based on the first-order steady state neutron transport equation, adopting the discrete ordinates method to disperse direction variables. Then a set of differential equations can be obtained and solved with the source iteration method. The 2-D transport module of ARES was capable of calculating k eff and fixed source problem with isotropic or anisotropic scattering in x-y geometry. The theoretical model was briefly introduced and series of benchmark problems were verified in this paper. Compared with the results given by the benchmark, the maximum relative deviation of k eff is 0.09% and the average relative deviation of flux density is about 0.60% in the BWR cells benchmark problem. As for the fixed source problem with isotropic and anisotropic scattering, the results of the 2-D transport module of ARES conform with DORT very well. These numerical results of benchmark problems preliminarily demonstrate that the development process of the 2-D transport module of ARES is right and it is able to provide high precision result. (authors)

2D deterministic radiation transport with the discontinuous finite element method

International Nuclear Information System (INIS)

Kershaw, D.; Harte, J.

1993-01-01

This report provides a complete description of the analytic and discretized equations for 2D deterministic radiation transport. This computational model has been checked against a wide variety of analytic test problems and found to give excellent results. We make extensive use of the discontinuous finite element method

Radiation doses arising from the air transport of radioactive materials

International Nuclear Information System (INIS)

Gelder, R.; Shaw, K.B.; Wilson, C.K.

1989-01-01

There is a compelling need for the transport of radioactive material by air because of the requirement by hospitals throughout the world for urgent delivery for medical purposes. Many countries have no radionuclide-producing capabilities and depend on imports: a range of such products is supplied from the United Kingdom. Many of these are short lived, which explains the need for urgent delivery. The only satisfactory method of delivery on a particular day to a particular destination is often by the use of scheduled passenger air service. The International Civil Aviation Organization's Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO 1987-1988), prescribe the detailed requirements applicable to the international transport of dangerous goods by air. Radioactive materials are required to be separated from persons and from undeveloped photographic films or plates: minimum distances as a function of the total sum of transport indexes are given in the Instructions. A study, which included the measurement and assessment of the radiation doses resulting from the transport of radioactive materials by air from the UK, has been performed by the National Radiological Protection Board (NRPB) on behalf of the Civil Aviation Authority (CAA) and the Department of Transport (DTp)

A NEW MONTE CARLO METHOD FOR TIME-DEPENDENT NEUTRINO RADIATION TRANSPORT

International Nuclear Information System (INIS)

Abdikamalov, Ernazar; Ott, Christian D.; O'Connor, Evan; Burrows, Adam; Dolence, Joshua C.; Löffler, Frank; Schnetter, Erik

2012-01-01

Monte Carlo approaches to radiation transport have several attractive properties such as simplicity of implementation, high accuracy, and good parallel scaling. Moreover, Monte Carlo methods can handle complicated geometries and are relatively easy to extend to multiple spatial dimensions, which makes them potentially interesting in modeling complex multi-dimensional astrophysical phenomena such as core-collapse supernovae. The aim of this paper is to explore Monte Carlo methods for modeling neutrino transport in core-collapse supernovae. We generalize the Implicit Monte Carlo photon transport scheme of Fleck and Cummings and gray discrete-diffusion scheme of Densmore et al. to energy-, time-, and velocity-dependent neutrino transport. Using our 1D spherically-symmetric implementation, we show that, similar to the photon transport case, the implicit scheme enables significantly larger timesteps compared with explicit time discretization, without sacrificing accuracy, while the discrete-diffusion method leads to significant speed-ups at high optical depth. Our results suggest that a combination of spectral, velocity-dependent, Implicit Monte Carlo and discrete-diffusion Monte Carlo methods represents a robust approach for use in neutrino transport calculations in core-collapse supernovae. Our velocity-dependent scheme can easily be adapted to photon transport.

A NEW MONTE CARLO METHOD FOR TIME-DEPENDENT NEUTRINO RADIATION TRANSPORT

Energy Technology Data Exchange (ETDEWEB)

Abdikamalov, Ernazar; Ott, Christian D.; O' Connor, Evan [TAPIR, California Institute of Technology, MC 350-17, 1200 E California Blvd., Pasadena, CA 91125 (United States); Burrows, Adam; Dolence, Joshua C. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States); Loeffler, Frank; Schnetter, Erik, E-mail: abdik@tapir.caltech.edu [Center for Computation and Technology, Louisiana State University, 216 Johnston Hall, Baton Rouge, LA 70803 (United States)

2012-08-20

Monte Carlo approaches to radiation transport have several attractive properties such as simplicity of implementation, high accuracy, and good parallel scaling. Moreover, Monte Carlo methods can handle complicated geometries and are relatively easy to extend to multiple spatial dimensions, which makes them potentially interesting in modeling complex multi-dimensional astrophysical phenomena such as core-collapse supernovae. The aim of this paper is to explore Monte Carlo methods for modeling neutrino transport in core-collapse supernovae. We generalize the Implicit Monte Carlo photon transport scheme of Fleck and Cummings and gray discrete-diffusion scheme of Densmore et al. to energy-, time-, and velocity-dependent neutrino transport. Using our 1D spherically-symmetric implementation, we show that, similar to the photon transport case, the implicit scheme enables significantly larger timesteps compared with explicit time discretization, without sacrificing accuracy, while the discrete-diffusion method leads to significant speed-ups at high optical depth. Our results suggest that a combination of spectral, velocity-dependent, Implicit Monte Carlo and discrete-diffusion Monte Carlo methods represents a robust approach for use in neutrino transport calculations in core-collapse supernovae. Our velocity-dependent scheme can easily be adapted to photon transport.

Compendium of Material Composition Data for Radiation Transport Modeling

International Nuclear Information System (INIS)

Williams, Ralph G.; Gesh, Christopher J.; Pagh, Richard T.

2006-01-01

Computational modeling of radiation transport problems including homeland security, radiation shielding and protection, and criticality safety all depend upon material definitions. This document has been created to serve two purposes: (1) to provide a quick reference of material compositions for analysts and (2) a standardized reference to reduce the differences between results from two independent analysts. Analysts are always encountering a variety of materials for which elemental definitions are not readily available or densities are not defined. This document provides a location where unique or hard to define materials will be located to reduce duplication in research for modeling purposes. Additionally, having a common set of material definitions helps to standardize modeling across PNNL and provide two separate researchers the ability to compare different modeling results from a common materials basis.

Computational transport phenomena for engineering analyses

CERN Document Server

Farmer, Richard C; Cheng, Gary C; Chen, Yen-Sen

2009-01-01

Computational Transport PhenomenaOverviewTransport PhenomenaAnalyzing Transport PhenomenaA Computational Tool: The CTP CodeVerification, Validation, and GeneralizationSummaryNomenclatureReferencesThe Equations of ChangeIntroductionDerivation of The Continuity EquationDerivation of The Species Continuity EquationDerivation of The Equation Of MotionDerivation of The General Energy EquationNon-Newtonian FluidsGeneral Property BalanceAnalytical and Approximate Solutions for the Equations of ChangeSummaryNomenclatureReferencesPhysical PropertiesOverviewReal-Fluid ThermodynamicsChemical Equilibrium

Energy and particle transport in the radiative divertor plasmas of DIII-D

International Nuclear Information System (INIS)

Leonard, A.W.; Allen, S.L.; Brooks, N.H.

1997-06-01

It has been argued that divertor energy transport dominated by parallel electron thermal conduction, or q parallel = -kT 5/2 2 dT e /ds parallel, leads to severe localization of the intense radiating region and ultimately limits the fraction of energy flux that can be radiated before striking the divertor target. This is due to the strong T 5/2 e dependence of electron heat conduction which results in very short spatial scales of the T e gradient at high power densities and low temperatures where deuterium and impurities radiate most effectively. However, we have greatly exceeded this constraint on DIII-D with deuterium gas puffing which reduces the peak heat flux to the divertor plate a factor of 5 while distributing the divertor radiation over a long length

Radiation transport methods for nuclear log assessment - an overview

International Nuclear Information System (INIS)

Badruzzaman, A.

1996-01-01

Methods of radiation transport have been applied to well-logging problems with nuclear sources since the early 1960s. Nuclear sondes are used in identifying rock compositions and fluid properties in reservoirs to predict the porosity and oil saturation. Early computational effort in nuclear logging used diffusion techniques. As computers became more powerful, deterministic transport methods and, finally, Monte Carlo methods were applied to solve these problems in three dimensions. Recently, the application has been extended to problems with a new generation of devices, including spectroscopic sondes that measure such quantities as the carbon/oxygen ratio to predict oil saturation and logging-while-drilling (LWD) sondes that take neutron and gamma measurements as they rotate in the borehole. These measurements present conditions that will be difficult to calibrate in the laboratory

Effect of gamma radiation on the transport of spin-labeled compounds across the erythrocyte membrane

International Nuclear Information System (INIS)

Gwozdzinski, K.; Bartosz, G.; Leyko, W.

1981-01-01

The effect of ionizing radiation on the non-electrolyte, anion and cation permeability of the erythrocyte membrane was studied by measurement of the reduction rate of appropriate nitroxyl derivatives. Irradiation of bovine erythrocytes in the dose-range of 2-50 krad resulted in a regular dose-dependent increase in the reduction rates of a cation (TEMPO-choline) and a hydrophobic non-electrolyte (TEMPO), and non-regular changes in the reduction rate of a hydrophilic non-electrolyte (TEMPOL). The permeation constant for TEMPO-choline also showed a non-regular response to radiation, similar to the response pattern of other red blood cell parameters. These results also demonstrate that the effects of radiation on the transport of various solutes can be used as a means of distinguishing between different channels of membrane transport. (orig.)

Concatenating algorithms for parallel numerical simulations coupling radiation hydrodynamics with neutron transport

International Nuclear Information System (INIS)

Mo Zeyao

2004-11-01

Multiphysics parallel numerical simulations are usually essential to simplify researches on complex physical phenomena in which several physics are tightly coupled. It is very important on how to concatenate those coupled physics for fully scalable parallel simulation. Meanwhile, three objectives should be balanced, the first is efficient data transfer among simulations, the second and the third are efficient parallel executions and simultaneously developments of those simulation codes. Two concatenating algorithms for multiphysics parallel numerical simulations coupling radiation hydrodynamics with neutron transport on unstructured grid are presented. The first algorithm, Fully Loosely Concatenation (FLC), focuses on the independence of code development and the independence running with optimal performance of code. The second algorithm. Two Level Tightly Concatenation (TLTC), focuses on the optimal tradeoffs among above three objectives. Theoretical analyses for communicational complexity and parallel numerical experiments on hundreds of processors on two parallel machines have showed that these two algorithms are efficient and can be generalized to other multiphysics parallel numerical simulations. In especial, algorithm TLTC is linearly scalable and has achieved the optimal parallel performance. (authors)

Reliability Analyses of Groundwater Pollutant Transport

Energy Technology Data Exchange (ETDEWEB)

Dimakis, Panagiotis

1997-12-31

This thesis develops a probabilistic finite element model for the analysis of groundwater pollution problems. Two computer codes were developed, (1) one using finite element technique to solve the two-dimensional steady state equations of groundwater flow and pollution transport, and (2) a first order reliability method code that can do a probabilistic analysis of any given analytical or numerical equation. The two codes were connected into one model, PAGAP (Probability Analysis of Groundwater And Pollution). PAGAP can be used to obtain (1) the probability that the concentration at a given point at a given time will exceed a specified value, (2) the probability that the maximum concentration at a given point will exceed a specified value and (3) the probability that the residence time at a given point will exceed a specified period. PAGAP could be used as a tool for assessment purposes and risk analyses, for instance the assessment of the efficiency of a proposed remediation technique or to study the effects of parameter distribution for a given problem (sensitivity study). The model has been applied to study the greatest self sustained, precipitation controlled aquifer in North Europe, which underlies Oslo`s new major airport. 92 refs., 187 figs., 26 tabs.

Status of the solar and infrared radiation submodels in the LLNL 1-D and 2-D chemical-transport models

International Nuclear Information System (INIS)

Grant, K.E.; Taylor, K.E.; Ellis, J.S.; Wuebbles, D.J.

1987-07-01

The authors have implemented a series of state of the art radiation transport submodels in previously developed one dimensional and two dimensional chemical transport models of the troposphere and stratosphere. These submodels provide the capability of calculating accurate solar and infrared heating rates. They are a firm basis for further radiation submodel development as well as for studying interactions between radiation and model dynamics under varying conditions of clear sky, clouds, and aerosols. 37 refs., 3 figs

Framework for assessing the effects of radioactive materials transportation

International Nuclear Information System (INIS)

Zoller, J.N.

1996-01-01

Radioactive materials transport may result in environmental effects during both incident-free and accident conditions. These effects may be caused by radiation exposure, pollutants, or physical trauma. Recent environmental impact analyses involving the transportation of radioactive materials are cited to provide examples of the types of activities which may be involved as well as the environmental effects which can be estimated

Effect of radiation and magnetic field on peristaltic transport of nanofluids through a porous space in a tapered asymmetric channel

Energy Technology Data Exchange (ETDEWEB)

Kothandapani, M., E-mail: mkothandapani@gmail.com [Department of Mathematics, University College of Engineering Arni, (A Constituent College of Anna University Chennai), Arni 632326, Tamil Nadu (India); Prakash, J., E-mail: prakashjayavel@yahoo.co.in [Department of Mathematics, Arulmigu Meenakshi Amman College of Engineering, Vadamavandal 604410, Tamil Nadu (India)

2015-03-15

Theoretical analyses on the effect of radiation and MHD on the peristaltic flow of a nanofluid through a porous medium in a two dimensional tapered asymmetric channel has been made. The nanofluid is assumed to be electrically conducting in the presence of a uniform magnetic field. The transport equation accounts the both Brownian motion and thermophoresis along with the radiation reaction. The problem has been further simplified with the authentic assumptions of long wavelength and small Reynolds number. The analytical expressions obtained for the axial velocity, stream function, temperature field, nanoparticle fraction field and pressure gradient provide satisfactory explanation. Influence of various parameters on the flow characteristics have been discussed with the help of graphical results. The trapping phenomenon has also been discussed in detail. - Highlights: • Combine effect of thermal radiation and MHD on the peristaltic flow of a Newtonian nanofluid are discussed. • This work may be first attempt dealing the study of Newtonian nanofluid flow in the porous tapered asymmetric channel. • The velocity, stream function, temperature field and nanoparticle fraction field provide satisfactory explanation with help of graphs.

Estimated effects on radiation doses from alternatives in a spent fuel transportation system

International Nuclear Information System (INIS)

Schneider, K.J.; Ross, W.A.; Smith, R.I.

1988-07-01

This paper contains the results of a study of estimated radiation doses to the public and workers from the transport of spent fuel from commercial nuclear power reactors to a geologic repository. A postulated reference rail/legal-weight truck transportation system is defined that would use current transportation technology, and provide a breakdown of activities and time/distance/dose-rate estimates for each activity within the system. Collective doses are estimated for each of the major activities at the reactor site, in transit, and at the repository receiving facility. Annual individual doses to the maximally exposed individuals or groups of individuals are also estimated. The dose-reduction potentials and costs are estimated for a total of 17 conceptual alternatives and subalternatives to the postulated reference system. Most of the alternatives evaluated are estimated to provide both cost and dose reductions. The major conclusion is that the potential exists for significant future reductions in radiation doses to the public and workers and for reductions in costs compared to those based on a continuation of past practices in the US

Estimated effects on radiation doses from alternatives in a spent fuel transportation system

International Nuclear Information System (INIS)

Schneider, K.J.; Ross, W.A.; Smith, R.I.

1988-01-01

This paper contains the results of a study of estimated radiation doses to the public and workers from the transport of spent fuel from commercial nuclear power reactors to a geologic repository. A postulated reference rail/legal-weight truck transportation system is defined that would use current transportation technology, and provide a breakdown of activities and time/distance/dose-rate estimates for each activity within the system. Collective doses are estimated for each of the major activities at the reactor site, in transit, and at the repository receiving facility. Annual individual doses to the maximally exposed individuals or groups of individuals also estimated. The dose-reduction potentials and costs are estimated for a total of 17 conceptual alternatives and subalternatives to the postulated reference system. Most of the alternatives evaluated are estimated to provide both cost and dose reductions. The major conclusion is that the potential exists for significant future reductions in radiation doses to the public and workers and for reductions in costs compared to those based on a continuation of past practices in the U.S

Global aerosol transport and consequences for the radiation budget

International Nuclear Information System (INIS)

Newiger, M.; Grassl, H.; Schussel, P.; Rehkopf, J.

1984-01-01

Man's activities may influence global climate by changing the atmospheric composition and surface characteristics and by waste heat. Most prominent within this discussion is the increase or decrease of radiatively active trace gases like CO/sub 2/, N/sub 2/O, O/sub 3/, and others. The general opinion is converging towards a greenhouse effect as a combined action of all trace gases, whose exact magnitude is uncertain mainly because of the unknown reaction of water cycle. The aim of our global 2-D (resolving latitude and height) aerosol transport model is the calculation of aerosol particle number density profiles as a function of latitude for present natural plus anthropogenic emissions. The aerosol transport model uses prescribed meridonal circulation, diffusivity factors and cloud climatology for January as well as July. All these latitude and height dependent input parameters were taken from well known sources. The fixed climatology excludes the feedback of aerosol particle parameter changes on mean circulation. However, the radiative parameters of six clouds types are modified, although they possess by adoption of the Telegadas and London (1954) cloud climatology prescribed amount and height. The inclusion of the feedback on mean circulation seems premature at present. Adding particles either accounting for natural emissions or natural anthropogenic emission and removing particles by all known sinks outside and within clouds gives us - for the stationary state - vertical profiles of aerosol number density in three sizes classes as a function of latitude. These profiles in turn are input for radiation flux calculations in clear and cloudy areas in order to assess net flux changes caused by the present aerosol load in comparison to a scenario without anthropogenic emissions. The net flux changes finally are compared to those calculated for increased CO/sub 2/ levels

Atmospheric radiation environment analyses based-on CCD camera at various mountain altitudes and underground sites

Directory of Open Access Journals (Sweden)

Li Cavoli Pierre

2016-01-01

Full Text Available The purpose of this paper is to discriminate secondary atmospheric particles and identify muons by measuring the natural radiative environment in atmospheric and underground locations. A CCD camera has been used as a cosmic ray sensor. The Low Noise Underground Laboratory of Rustrel (LSBB, France gives the access to a unique low-noise scientific environment deep enough to ensure the screening from the neutron and proton radiative components. Analyses of the charge levels in pixels of the CCD camera induced by radiation events and cartographies of the charge events versus the hit pixel are proposed.

A FORMALISM FOR COVARIANT POLARIZED RADIATIVE TRANSPORT BY RAY TRACING

International Nuclear Information System (INIS)

Gammie, Charles F.; Leung, Po Kin

2012-01-01

We write down a covariant formalism for polarized radiative transfer appropriate for ray tracing through a turbulent plasma. The polarized radiation field is represented by the polarization tensor (coherency matrix) N αβ ≡ (a α k a* β k ), where a k is a Fourier coefficient for the vector potential. Using Maxwell's equations, the Liouville-Vlasov equation, and the WKB approximation, we show that the transport equation in vacuo is k μ ∇ μ N αβ = 0. We show that this is equivalent to Broderick and Blandford's formalism based on invariant Stokes parameters and a rotation coefficient, and suggest a modification that may reduce truncation error in some situations. Finally, we write down several alternative approaches to integrating the transfer equation.

Review of Hybrid (Deterministic/Monte Carlo) Radiation Transport Methods, Codes, and Applications at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Wagner, John C.; Peplow, Douglas E.; Mosher, Scott W.; Evans, Thomas M.

2010-01-01

This paper provides a review of the hybrid (Monte Carlo/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux, dose, or reaction rate at a particular location) and (2) Forward Weighted CADIS (FW-CADIS) for optimizing distributions (e.g., mesh tallies over all or part of the problem space) or multiple localized detector regions (e.g., simultaneous optimization of two or more localized tally regions). The two methods have been implemented and automated in both the MAVRIC sequence of SCALE 6 and ADVANTG, a code that works with the MCNP code. As implemented, the methods utilize the results of approximate, fast-running 3-D discrete ordinates transport calculations (with the Denovo code) to generate consistent space- and energy-dependent source and transport (weight windows) biasing parameters. These methods and codes have been applied to many relevant and challenging problems, including calculations of PWR ex-core thermal detector response, dose rates throughout an entire PWR facility, site boundary dose from arrays of commercial spent fuel storage casks, radiation fields for criticality accident alarm system placement, and detector response for special nuclear material detection scenarios and nuclear well-logging tools. Substantial computational speed-ups, generally O(10 2-4 ), have been realized for all applications to date. This paper provides a brief review of the methods, their implementation, results of their application, and current development activities, as well as a considerable list of references for readers seeking more information about the methods and/or their applications.

Review of Hybrid (Deterministic/Monte Carlo) Radiation Transport Methods, Codes, and Applications at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Wagner, John C.; Peplow, Douglas E.; Mosher, Scott W.; Evans, Thomas M.

2010-01-01

This paper provides a review of the hybrid (Monte Carlo/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux, dose, or reaction rate at a particular location) and (2) Forward Weighted CADIS (FW-CADIS) for optimizing distributions (e.g., mesh tallies over all or part of the problem space) or multiple localized detector regions (e.g., simultaneous optimization of two or more localized tally regions). The two methods have been implemented and automated in both the MAVRIC sequence of SCALE 6 and ADVANTG, a code that works with the MCNP code. As implemented, the methods utilize the results of approximate, fast-running 3-D discrete ordinates transport calculations (with the Denovo code) to generate consistent space- and energy-dependent source and transport (weight windows) biasing parameters. These methods and codes have been applied to many relevant and challenging problems, including calculations of PWR ex-core thermal detector response, dose rates throughout an entire PWR facility, site boundary dose from arrays of commercial spent fuel storage casks, radiation fields for criticality accident alarm system placement, and detector response for special nuclear material detection scenarios and nuclear well-logging tools. Substantial computational speed-ups, generally O(102-4), have been realized for all applications to date. This paper provides a brief review of the methods, their implementation, results of their application, and current development activities, as well as a considerable list of references for readers seeking more information about the methods and/or their applications.

Review of hybrid (deterministic/Monte Carlo) radiation transport methods, codes, and applications at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Wagner, J.C.; Peplow, D.E.; Mosher, S.W.; Evans, T.M.

2010-01-01

This paper provides a review of the hybrid (Monte Carlo/deterministic) radiation transport methods and codes used at the Oak Ridge National Laboratory and examples of their application for increasing the efficiency of real-world, fixed-source Monte Carlo analyses. The two principal hybrid methods are (1) Consistent Adjoint Driven Importance Sampling (CADIS) for optimization of a localized detector (tally) region (e.g., flux, dose, or reaction rate at a particular location) and (2) Forward Weighted CADIS (FW-CADIS) for optimizing distributions (e.g., mesh tallies over all or part of the problem space) or multiple localized detector regions (e.g., simultaneous optimization of two or more localized tally regions). The two methods have been implemented and automated in both the MAVRIC sequence of SCALE 6 and ADVANTG, a code that works with the MCNP code. As implemented, the methods utilize the results of approximate, fast-running 3-D discrete ordinates transport calculations (with the Denovo code) to generate consistent space- and energy-dependent source and transport (weight windows) biasing parameters. These methods and codes have been applied to many relevant and challenging problems, including calculations of PWR ex-core thermal detector response, dose rates throughout an entire PWR facility, site boundary dose from arrays of commercial spent fuel storage casks, radiation fields for criticality accident alarm system placement, and detector response for special nuclear material detection scenarios and nuclear well-logging tools. Substantial computational speed-ups, generally O(10 2-4 ), have been realized for all applications to date. This paper provides a brief review of the methods, their implementation, results of their application, and current development activities, as well as a considerable list of references for readers seeking more information about the methods and/or their applications. (author)

Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools

International Nuclear Information System (INIS)

Jacobs, D.B.; Berenski, C.J.; Spangler, R.A.; Jung, C.Y.

1987-01-01

The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior to and after insulin treatment, respectively. In the case of microsomal membranes, however, inactivation data showed anomalously low radiation sensitivities at low radiation doses, which may be interpreted as indicating the presence of a radiation-sensitive inhibitor. These results suggest that the adipocyte glucose transporter occurs as a monomer in the plasma membrane while existing in the intracellular reserve pool either as a homodimer or as a stoichiometric complex with a protein of an approximately equal size

Overview and applications of the Monte Carlo radiation transport kit at LLNL

International Nuclear Information System (INIS)

Sale, K. E.

1999-01-01

Modern Monte Carlo radiation transport codes can be applied to model most applications of radiation, from optical to TeV photons, from thermal neutrons to heavy ions. Simulations can include any desired level of detail in three-dimensional geometries using the right level of detail in the reaction physics. The technology areas to which we have applied these codes include medical applications, defense, safety and security programs, nuclear safeguards and industrial and research system design and control. The main reason such applications are interesting is that by using these tools substantial savings of time and effort (i.e. money) can be realized. In addition it is possible to separate out and investigate computationally effects which can not be isolated and studied in experiments. In model calculations, just as in real life, one must take care in order to get the correct answer to the right question. Advancing computing technology allows extensions of Monte Carlo applications in two directions. First, as computers become more powerful more problems can be accurately modeled. Second, as computing power becomes cheaper Monte Carlo methods become accessible more widely. An overview of the set of Monte Carlo radiation transport tools in use a LLNL will be presented along with a few examples of applications and future directions

High-order discontinuous Galerkin nonlocal transport and energy equations scheme for radiation hydrodynamics

Czech Academy of Sciences Publication Activity Database

Holec, M.; Limpouch, J.; Liska, R.; Weber, Stefan A.

2017-01-01

Roč. 83, č. 10 (2017), s. 779-797 ISSN 0271-2091 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : radiation hydrodynamics * nonlocal transport * Knudsen number * multigroup diffusion * radiation coupling Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.652, year: 2016

Confinement mechanisms in the radiatively improved mode

NARCIS (Netherlands)

Tokar, M. Z.; R. Jaspers,; Koslowski, H. R.; Kramer-Flecken, A.; Messiaen, A. M.; Ongena, J.; Rogister, A. A.; Unterberg, B.; Weynants, R. R.

1999-01-01

The characteristics of the toroidal ion temperature gradient (ITG) instability, considered as the main source of anomalous transport in the low (L) confinement mode of tokamaks, are analysed for the conditions of the radiatively improved (RI) mode triggered by seeding of impurities. Based on

Radiation shielding for fusion reactors

International Nuclear Information System (INIS)

Santoro, R.T.

2000-01-01

Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. (author)

Radiative transport and collisional transfer of excitation energy in Cs vapors mixed with Ar or He

International Nuclear Information System (INIS)

Vadla, Cedomil; Horvatic, Vlasta; Niemax, Kay

2003-01-01

This paper is a review (with a few original additions) on the radiative transport and collisional transfer of energy in laser-excited cesium vapors in the presence of argon or helium. Narrow-band excitation of lines with Lorentz, Doppler and Voigt profiles is studied in order to calculate effective rates for pumping of spectral lines with profiles comprising inhomogeneous broadening components. The radiative transport of excitation energy is considered, and a new, simple and robust, but accurate theoretical method for quantitative treatment of radiation trapping in relatively optically thin media is presented. Furthermore, comprehensive lists of experimental values for the excitation energy transfer cross-sections related to thermal collisions in Cs-Ar and Cs-He mixtures are given. Within the collected cross-section data sets, specific regularities with respect to the energy defect, as well as the temperature, are discerned. A particular emphasis is put on the radiative and collisional processes important for the optimization of resonance-fluorescence imaging atomic filters based on Cs-noble gas systems

Utilization of a photon transport code to investigate radiation therapy treatment planning quantities and techniques

International Nuclear Information System (INIS)

Palta, J.R.

1981-01-01

A versatile computer program MORSE, based on neutron and photon transport theory has been utilzed to investigate radiation therapy treatment planning quantities and techniques. A multi-energy group representation of transport equation provides a concise approach in utilizing Monte Carlo numerical techniques to multiple radiation therapy treatment planning problems. Central axis total and scattered dose distributions for homogeneous and inhomogeneous water phantoms are calculated and the correction factor for lung and bone inhomogeneities are also evaluated. Results show that Monte Carlo calculations based on multi-energy group tansport theory predict the depth dose distributions that are in good agreement with available experimental data. Central axis depth dose distributions for a bremsstrahlung spectrum from a linear accelerator is also calculated to exhibit the versatility of the computer program in handling multiple radiation therapy problems. A novel approach is undertaken to study the dosimetric properties of brachytherapy sources

Analysis of radiation doses for a transportation system and its interface operations for commercial spent fuel

International Nuclear Information System (INIS)

Schneider, K.J.; Ross, W.A.; Smith, R.I.; Wilmot, E.L.

1987-07-01

This paper gives the results of estimates of aggregated radiation doses to the affected public and workers in the US that would be associated with loading spent fuel at the reactors, transporting the spent fuel by truck and rail, and receiving and unloading the spent fuel at a deep geological repository. The estimates are for a postulated transportation-related system using current state-of-the-art technology, if employed in the high-level waste management system in the future, and the approximate dose reduction from some potential system improvements. The results of the study provide a starting point for the US Department of Energy (DOE) to develop an improved transportation system that is cost effective, safe, and results in low radiation doses. 4 refs., 1 figs., 5 tabs

Ion transport in roots of cotton seedlings under the effect of gamma-radiation

International Nuclear Information System (INIS)

Kasymov, A.K.

1976-01-01

It has been found that small doses (0.1 to 0.5kR) increase the ion transport (K + and Na + ) in seedling roots, and relatively high radiation doses (25 to 100 kR) markedly decrease it. ATPase activity varied with the dose. Mgsup(++)-, Na + - and K + -activated ATPases were more sensitive than a background ATPase. It is suggested that high radiation doses destroy the work of the sodium-potassium pump of cotton root cells inhibiting the activity of the transfer ATPase

Current status of radiation transport tools for proliferation and terrorism prevention

International Nuclear Information System (INIS)

Sale, K.E.

2004-01-01

We present the current status and future plans for the set of calculational tools and data bases developed and maintained at LLNL. The calculational tools include the Monte Carlo codes TART and COG as well as the deterministic code ARDRA. In addition to these codes presently in use there is a major development effort for a new massively parallel transport code. An important part of the capability we're developing is a sophisticated user interface, based on a commercial 3-D modeling product, to improve the model development process. A major part of this user interface tool is being developed by Strela under the Nuclear Cities Initiative. Strela has developed a hub-and-spoke technology for code input interconversions (between COG, TART and MCNP) and will produce the plug-ins that extend the capabilities of the 3-D modeler for use as a radiation transport input generator. The major advantages of this approach are the built-in user interface for 3-D modeling and the ability to read a large variety of CAD-file formats. In addition to supporting our current radiation transport codes and developing new capabilities we are working on some nuclear data needs for homeland security. These projects are carried out and the Lawrence Berkeley National Laboratory 88' cyclotron and at the Institute for Nuclear Research of the Nation Academy of Science of Ukraine under and STCU contract. (author)

Sensitivity of a two-dimensional chemistry-transport model to changes in parameterizations of radiative processes

International Nuclear Information System (INIS)

Grant, K.E.; Ellingson, R.G.; Wuebbles, D.J.

1988-08-01

Radiative processes strongly effect equilibrium trace gas concentrations both directly, through photolysis reactions, and indirectly through temperature and transport processes. As part of our continuing radiative submodel development and validation, we have used the LLNL 2-D chemical-radiative-transport (CRT) model to investigate the net sensitivity of equilibrium ozone concentrations to several changes in radiative forcing. Doubling CO 2 from 300 ppmv to 600 ppmv resulted in a temperature decrease of 5 K to 8 K in the middle stratosphere along with an 8% to 16% increase in ozone in the same region. Replacing our usual shortwave scattering algorithms with a simplified Rayleigh algorithm led to a 1% to 2% increase in ozone in the lower stratosphere. Finally, modifying our normal CO 2 cooling rates by corrections derived from line-by-line calculations resulted in several regions of heating and cooling. We observed temperature changes on the order of 1 K to 1.5 K with corresponding changes of 0.5% to 1.5% in O 3 . Our results for doubled CO 2 compare favorably with those by other authors. Results for our two perturbation scenarios stress the need for accurately modeling radiative processes while confirming the general validity of current 2-D CRT models. 15 refs., 5 figs

Numerical simulations for radiation hydrodynamics. 2: Transport limit

International Nuclear Information System (INIS)

Dai, W.W.; Woodward, P.R.

2000-01-01

A finite difference scheme is proposed for two-dimensional radiation hydrodynamical equations in the transport limit. The scheme is of Godunov-type, in which the set of time-averaged flux needed in the scheme is calculated through Riemann problems solved. In the scheme, flow signals are explicitly treated, while radiation signals are implicitly treated. Flow fields and radiation fields are updated simultaneously. An iterative approach is proposed to solve the set of nonlinear algebraic equations arising from the implicitness of the scheme. The sweeping method used in the scheme significantly reduces the number of iterations or computer CPU time needed. A new approach to further accelerate the convergence is proposed, which further reduces the number of iterations needed by more than one order. No matter how many cells radiation signals propagate in one time step, only an extremely small number of iterations are needed in the scheme, and each iteration costs only about 0.8% of computer CPU time which is needed for one time step of a second order accurate and fully explicit scheme. Two-dimensional problems are treated through a dimensionally split technique. Therefore, iterations for solving the set of algebraic equations are carried out only in each one-dimensional sweep. Through numerical examples it is shown that the scheme keeps the principle advantages of Godunov schemes for flow motion. In the time scale of flow motion numerical results are the same as those obtained from a second order accurate and fully explicit scheme. The acceleration of the convergence proposed in this paper may be directly applied to other hyperbolic systems. This study is important for laser fusion and astrophysics

Transport of radioactive materials: the need for radiation protection programmes

International Nuclear Information System (INIS)

Masinza, S.A.

2004-01-01

The increase in the use of radioactive materials worldwide requires that these materials be moved from production sites to the end user or in the case of radioactive waste, from the waste generator to the repository. Tens of millions of packages containing radioactive material are consigned for transport each year throughout the world. The amount of radioactive material in these packages varies from negligible quantities in shipments of consumer products to very large quantities of shipments of irradiated nuclear fuel. Transport is the main way in which the radioactive materials being moved get into the public domain. The public is generally unaware of the lurking danger when transporting these hazardous goods. Thus radiation protection programmes are important to assure the public of the certainty of their safety during conveyance of these materials. Radioactive material is transported by land (road and rail), inland waterways, sea/ocean and air. These modes of transport are regulated by international 'modal' regulations. The international community has formulated controls to reduce the number of accidents and mitigate their consequences should they happen. When accidents involving the transport of radioactive material occur, it could result in injury, loss of life and pollution of the environment. In order to ensure the safety of people, property and the environment, national and international transport regulations have been developed. The appropriate authorities in each state utilise them to control the transport of radioactive material. Stringent measures are required in these regulations to ensure adequate containment, shielding and the prevention of criticality in all spheres of transport, i.e. routine, minor incidents and accident conditions. Despite the extensive application of these stringent safety controls, transport accidents involving packages containing radioactive material have occurred and will continue to occur. When a transport accident occurs, it

A review of the radiation exposure of transport personnel during the radioactive waste sea disposal operations from 1977-1982

International Nuclear Information System (INIS)

Mairs, J.H.

1985-06-01

The period of the review was chosen to give an account of the recent radiation exposures of transport personnel, which may serve as an indicator of possible future exposures associated with sea disposal operations. The annual radiation exposure of transport personnel has shown a significant reduction during the period of the review. These dose savings have been achieved despite a general increase in the quantities of wastes dumped. This is probably due to the improved shielding of packages and radiologically improved working procedures. If ocean disposal of solid or solidified radioactive waste was to be resumed the exposure of transport personnel might be expected to be comparable to the low doses received in the early 1980s. However, changes in packaging, handling procedures and frequency of movements would have major effects on radiation exposure. (author)

STP-ECRTS - THERMAL AND GAS ANALYSES FOR SLUDGE TRANSPORT AND STORAGE CONTAINER (STSC) STORAGE AT T PLANT

Energy Technology Data Exchange (ETDEWEB)

CROWE RD; APTHORPE R; LEE SJ; PLYS MG

2010-04-29

The Sludge Treatment Project (STP) is responsible for the disposition of sludge contained in the six engineered containers and Settler tank within the 105-K West (KW) Basin. The STP is retrieving and transferring sludge from the Settler tank into engineered container SCS-CON-230. Then, the STP will retrieve and transfer sludge from the six engineered containers in the KW Basin directly into a Sludge Transport and Storage Containers (STSC) contained in a Sludge Transport System (STS) cask. The STSC/STS cask will be transported to T Plant for interim storage of the STSC. The STS cask will be loaded with an empty STSC and returned to the KW Basin for loading of additional sludge for transportation and interim storage at T Plant. CH2MHILL Plateau Remediation Company (CHPRC) contracted with Fauske & Associates, LLC (FAI) to perform thermal and gas generation analyses for interim storage of STP sludge in the Sludge Transport and Storage Container (STSCs) at T Plant. The sludge types considered are settler sludge and sludge originating from the floor of the KW Basin and stored in containers 210 and 220, which are bounding compositions. The conditions specified by CHPRC for analysis are provided in Section 5. The FAI report (FAI/10-83, Thermal and Gas Analyses for a Sludge Transport and Storage Container (STSC) at T Plant) (refer to Attachment 1) documents the analyses. The process considered was passive, interim storage of sludge in various cells at T Plant. The FATE{trademark} code is used for the calculation. The results are shown in terms of the peak sludge temperature and hydrogen concentrations in the STSC and the T Plant cell. In particular, the concerns addressed were the thermal stability of the sludge and the potential for flammable gas mixtures. This work was performed with preliminary design information and a preliminary software configuration.

A new spherical harmonics scheme for multi-dimensional radiation transport I. Static matter configurations

Energy Technology Data Exchange (ETDEWEB)

Radice, David, E-mail: david.radice@aei.mpg.de [Max Planck Institute für Gravitationsphysik, Albert Einstein Institute, Potsdam (Germany); Abdikamalov, Ernazar [TAPIR, California Institute of Technology, Pasadena, CA (United States); Rezzolla, Luciano [Max Planck Institute für Gravitationsphysik, Albert Einstein Institute, Potsdam (Germany); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA (United States); Ott, Christian D. [TAPIR, California Institute of Technology, Pasadena, CA (United States)

2013-06-01

Recent work by McClarren and Hauck (2010) [31] suggests that the filtered spherical harmonics method represents an efficient, robust, and accurate method for radiation transport, at least in the two-dimensional (2D) case. We extend their work to the three-dimensional (3D) case and find that all of the advantages of the filtering approach identified in 2D are present also in the 3D case. We reformulate the filter operation in a way that is independent of the timestep and of the spatial discretization. We also explore different second- and fourth-order filters and find that the second-order ones yield significantly better results. Overall, our findings suggest that the filtered spherical harmonics approach represents a very promising method for 3D radiation transport calculations.

A new spherical harmonics scheme for multi-dimensional radiation transport I. Static matter configurations

International Nuclear Information System (INIS)

Radice, David; Abdikamalov, Ernazar; Rezzolla, Luciano; Ott, Christian D.

2013-01-01

Recent work by McClarren and Hauck (2010) [31] suggests that the filtered spherical harmonics method represents an efficient, robust, and accurate method for radiation transport, at least in the two-dimensional (2D) case. We extend their work to the three-dimensional (3D) case and find that all of the advantages of the filtering approach identified in 2D are present also in the 3D case. We reformulate the filter operation in a way that is independent of the timestep and of the spatial discretization. We also explore different second- and fourth-order filters and find that the second-order ones yield significantly better results. Overall, our findings suggest that the filtered spherical harmonics approach represents a very promising method for 3D radiation transport calculations

The new deterministic 3-D radiation transport code Multitrans: C5G7 MOX fuel assembly benchmark

International Nuclear Information System (INIS)

Kotiluoto, P.

2003-01-01

The novel deterministic three-dimensional radiation transport code MultiTrans is based on combination of the advanced tree multigrid technique and the simplified P3 (SP3) radiation transport approximation. In the tree multigrid technique, an automatic mesh refinement is performed on material surfaces. The tree multigrid is generated directly from stereo-lithography (STL) files exported by computer-aided design (CAD) systems, thus allowing an easy interface for construction and upgrading of the geometry. The deterministic MultiTrans code allows fast solution of complicated three-dimensional transport problems in detail, offering a new tool for nuclear applications in reactor physics. In order to determine the feasibility of a new code, computational benchmarks need to be carried out. In this work, MultiTrans code is tested for a seven-group three-dimensional MOX fuel assembly transport benchmark without spatial homogenization (NEA C5G7 MOX). (author)

Radiation field calculation in the vicinity of Russian radioisotope generator sources

Energy Technology Data Exchange (ETDEWEB)

Pretzsch, Gunter; Hummelsheim, Klemens; Bogorinski, Peter [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Kurfuerstendamm 200, 10719 Berlin (Germany)

2005-07-01

Germany supports the Russian Federation in the framework of the G8 Global Partnership programme to secure nuclear and radioactive materials against misuse and proliferation. In this context, GRS, on behalf of the German Foreign Office, is coordinating activities to remove disused radioisotope thermoelectric generators (RITEG) from the Baltic Sea which serve as power supply for marine lighthouses and their replacement by alternative energy sources. Further the planned project includes transportation to an interim storage, the storage equipped with radiation monitoring and physical protection measures, later transportation for reprocessing to the Mayak Production Association, where the RITEG will be dismantled in a hot cell and encapsulated radioactive source will be vitrified and stored as radioactive waste. For the whole project safety analyses are to be performed e.g. to meet radiation protection requirements. In the present paper modelling and calculation of radiation fields in the vicinity of RITEG as a basis for safety analyses is reported. (authors)

Parametric assessments on hydrogenic species transport in CVD-diamond vacuum windows used in ITER ECRH

Energy Technology Data Exchange (ETDEWEB)

Moreno, C.; Sedano, L.A.; Fernandez, A. [EURATOM-CIEMAT Association, Madrid (Spain)

2007-07-01

Insulators used as H and CD and Diagnostic vacuum windows (VW) in ITER may become modified by surface intake and bulk transport of hydrogenic species. VW, operating under severe radiation levels, have a primary safety role as tritium confinement barriers. Ionizing radiation enhances the (H') uptake and release at surfaces and diffusion rates in the bulk. Radiation damage modifies the material's bulk trapped inventories by increasing steady state trapping centre concentrations. An experimental programme is ongoing at CIEMAT, to quantify radiation effects on H transport characteristics and also the possible impact on the VW. The reference material for ECRH VW is CVD diamond. As a parallel activity, parametric transport assessments are being made in order to obtain a wide evaluation of permeation fluxes, ranges, and soluted/trapped inventories in CVD diamond. Transport models have been developed based on extended capabilities of finite differences integrator tool TMAP7. Special attention is paid to radiation parameters defining inputs acting on transport magnitudes. These inputs have been analysed by using ionizing/damage radiation transport tools such as MCNPX/SRIM. VW operational scenarios are discussed with special attention being paid to the ITER design assumptions for the values of H-species source terms (neutrals and implanted) in the ECRH system. The available material transport database with and without radiation is discussed and taken as reference for this parametric exercise. Permeation fluxes through base materials are shown to be below DRG limits established for ITER. (orig.)

Stationary neutrino radiation transport by maximum entropy closure

International Nuclear Information System (INIS)

Bludman, S.A.

1994-11-01

The authors obtain the angular distributions that maximize the entropy functional for Maxwell-Boltzmann (classical), Bose-Einstein, and Fermi-Dirac radiation. In the low and high occupancy limits, the maximum entropy closure is bounded by previously known variable Eddington factors that depend only on the flux. For intermediate occupancy, the maximum entropy closure depends on both the occupation density and the flux. The Fermi-Dirac maximum entropy variable Eddington factor shows a scale invariance, which leads to a simple, exact analytic closure for fermions. This two-dimensional variable Eddington factor gives results that agree well with exact (Monte Carlo) neutrino transport calculations out of a collapse residue during early phases of hydrostatic neutron star formation

Implementation, capabilities, and benchmarking of Shift, a massively parallel Monte Carlo radiation transport code

International Nuclear Information System (INIS)

Pandya, Tara M.; Johnson, Seth R.; Evans, Thomas M.; Davidson, Gregory G.; Hamilton, Steven P.; Godfrey, Andrew T.

2015-01-01

This paper discusses the implementation, capabilities, and validation of Shift, a massively parallel Monte Carlo radiation transport package developed and maintained at Oak Ridge National Laboratory. It has been developed to scale well from laptop to small computing clusters to advanced supercomputers. Special features of Shift include hybrid capabilities for variance reduction such as CADIS and FW-CADIS, and advanced parallel decomposition and tally methods optimized for scalability on supercomputing architectures. Shift has been validated and verified against various reactor physics benchmarks and compares well to other state-of-the-art Monte Carlo radiation transport codes such as MCNP5, CE KENO-VI, and OpenMC. Some specific benchmarks used for verification and validation include the CASL VERA criticality test suite and several Westinghouse AP1000 ® problems. These benchmark and scaling studies show promising results

The use of symbolic computation in radiative, energy, and neutron transport calculations. Technical report, 15 August 1992--14 August 1994

International Nuclear Information System (INIS)

Frankel, J.I.

1995-01-01

This investigation uses symbolic computation in developing analytical methods and general computational strategies for solving both linear and nonlinear, regular and singular, integral and integro-differential equations which appear in radiative and combined mode energy transport. This technical report summarizes the research conducted during the first nine months of the present investigation. The use of Chebyshev polynomials augmented with symbolic computation has clearly been demonstrated in problems involving radiative (or neutron) transport, and mixed-mode energy transport. Theoretical issues related to convergence, errors, and accuracy have also been pursued. Three manuscripts have resulted from the funded research. These manuscripts have been submitted to archival journals. At the present time, an investigation involving a conductive and radiative medium is underway. The mathematical formulation leads to a system of nonlinear, weakly-singular integral equations involving the unknown temperature and various Legendre moments of the radiative intensity in a participating medium. Some preliminary results are presented illustrating the direction of the proposed research

Development of comprehensive models for opacities and radiation transport for IFE systems

International Nuclear Information System (INIS)

Tolkach, V.; Morozov, V.; Hassanein, A.

2003-01-01

An ignition in an inertial confinement fusion (ICF) reactor results in X-ray spectra and ion fluxes moving toward the chamber wall with different velocities. During flight, parts of the energy will be deposited either in the residual and/or protective chamber gas or in the initial vapor cloud developed near the wall surface from vaporization. The deposited energy will be re-radiated to the chamber wall long after the ignition process. The exact amount of energy deposited/radiated and time of deposition are key issues in evaluating the chamber response and the economical feasibility of an ICF reactor. The radiation processes in the protective gas layer or in the vapor cloud developed above the first wall play an important role in the overall dynamics of the ICF chamber. A self-consistent field method has been developed to calculate ionization potentials, atom and ion energy levels, transition probabilities, and other atomic properties used to calculate thermodynamic and optical characteristics of the plasma by means of collisional-radiation equilibrium (CRE). The methodology of solving radiation transport equations in spherical geometry and the dependence of results on the chosen theoretical model are demonstrated using the method of inward/outward directions

Solar Radiation Transport in the Cloudy Atmosphere: A 3D Perspective on Observations and Climate Impacts

Science.gov (United States)

Davis, Anthony B.; Marshak, Alexander

2010-01-01

The interplay of sunlight with clouds is a ubiquitous and often pleasant visual experience, but it conjures up major challenges for weather, climate, environmental science and beyond. Those engaged in the characterization of clouds (and the clear air nearby) by remote sensing methods are even more confronted. The problem comes, on the one hand, from the spatial complexity of real clouds and, on the other hand, from the dominance of multiple scattering in the radiation transport. The former ingredient contrasts sharply with the still popular representation of clouds as homogeneous plane-parallel slabs for the purposes of radiative transfer computations. In typical cloud scenes the opposite asymptotic transport regimes of diffusion and ballistic propagation coexist. We survey the three-dimensional (3D) atmospheric radiative transfer literature over the past 50 years and identify three concurrent and intertwining thrusts: first, how to assess the damage (bias) caused by 3D effects in the operational 1D radiative transfer models? Second, how to mitigate this damage? Finally, can we exploit 3D radiative transfer phenomena to innovate observation methods and technologies? We quickly realize that the smallest scale resolved computationally or observationally may be artificial but is nonetheless a key quantity that separates the 3D radiative transfer solutions into two broad and complementary classes: stochastic and deterministic. Both approaches draw on classic and contemporary statistical, mathematical and computational physics.

The Method of Manufactured Solutions for RattleSnake A SN Radiation Transport Solver Inside the MOOSE Framework

International Nuclear Information System (INIS)

Wang, Yaqi

2012-01-01

The Method of Manufactured Solutions (MMS) is an accepted technique to verify that a numerical discretization for the radiation transport equation has been implemented correctly. This technique offers a few advantages over other methods such as benchmark problems or analytical solutions. The solution can be manufactured such that properties for the angular flux are either stressed or preserved. For radiation transport, these properties can include desired smoothness, positiveness and arbitrary order of anisotropy in angle. Another advantage is that the angular flux solution can be manufactured for multidimensional problems where analytical solutions are difficult to obtain in general.

Validation of comprehensive space radiation transport code

International Nuclear Information System (INIS)

Shinn, J.L.; Simonsen, L.C.; Cucinotta, F.A.

1998-01-01

The HZETRN code has been developed over the past decade to evaluate the local radiation fields within sensitive materials on spacecraft in the space environment. Most of the more important nuclear and atomic processes are now modeled and evaluation within a complex spacecraft geometry with differing material components, including transition effects across boundaries of dissimilar materials, are included. The atomic/nuclear database and transport procedures have received limited validation in laboratory testing with high energy ion beams. The codes have been applied in design of the SAGE-III instrument resulting in material changes to control injurious neutron production, in the study of the Space Shuttle single event upsets, and in validation with space measurements (particle telescopes, tissue equivalent proportional counters, CR-39) on Shuttle and Mir. The present paper reviews the code development and presents recent results in laboratory and space flight validation

Radiation shielding for TFTR DT diagnostics

International Nuclear Information System (INIS)

Ku, L.P.; Johnson, D.W.; Liew, S.L.

1994-01-01

The authors illustrate the designs of radiation shielding for the TFTR DT diagnostics using the ACX and TVTS systems as specific examples. The main emphasis here is on the radiation transport analyses carried out in support of the designs. Initial results from the DT operation indicate that the diagnostics have been functioning as anticipated and the shielding designs are satisfactory. The experience accumulated in the shielding design for the TFTR DT diagnostics should be useful and applicable to future devices, such as TPX and ITER, where many similar diagnostic systems are expected to be used

Sensitivity analyses of a colloid-facilitated contaminant transport model for unsaturated heterogeneous soil conditions.

Science.gov (United States)

Périard, Yann; José Gumiere, Silvio; Rousseau, Alain N.; Caron, Jean

2013-04-01

Certain contaminants may travel faster through soils when they are sorbed to subsurface colloidal particles. Indeed, subsurface colloids may act as carriers of some contaminants accelerating their translocation through the soil into the water table. This phenomenon is known as colloid-facilitated contaminant transport. It plays a significant role in contaminant transport in soils and has been recognized as a source of groundwater contamination. From a mechanistic point of view, the attachment/detachment of the colloidal particles from the soil matrix or from the air-water interface and the straining process may modify the hydraulic properties of the porous media. Šimůnek et al. (2006) developed a model that can simulate the colloid-facilitated contaminant transport in variably saturated porous media. The model is based on the solution of a modified advection-dispersion equation that accounts for several processes, namely: straining, exclusion and attachement/detachement kinetics of colloids through the soil matrix. The solutions of these governing, partial differential equations are obtained using a standard Galerkin-type, linear finite element scheme, implemented in the HYDRUS-2D/3D software (Šimůnek et al., 2012). Modeling colloid transport through the soil and the interaction of colloids with the soil matrix and other contaminants is complex and requires the characterization of many model parameters. In practice, it is very difficult to assess actual transport parameter values, so they are often calibrated. However, before calibration, one needs to know which parameters have the greatest impact on output variables. This kind of information can be obtained through a sensitivity analysis of the model. The main objective of this work is to perform local and global sensitivity analyses of the colloid-facilitated contaminant transport module of HYDRUS. Sensitivity analysis was performed in two steps: (i) we applied a screening method based on Morris' elementary

Radiation transport code with adaptive Mesh Refinement: acceleration techniques and applications

International Nuclear Information System (INIS)

Velarde, Pedro; Garcia-Fernaandez, Carlos; Portillo, David; Barbas, Alfonso

2011-01-01

We present a study of acceleration techniques for solving Sn radiation transport equations with Adaptive Mesh Refinement (AMR). Both DSA and TSA are considered, taking into account the influence of the interaction between different levels of the mesh structure and the order of approximation in angle. A Hybrid method is proposed in order to obtain better convergence rate and lower computer times. Some examples are presented relevant to ICF and X ray secondary sources. (author)

An evaluation system for electronic retrospective analyses in radiation oncology: implemented exemplarily for pancreatic cancer

Science.gov (United States)

Kessel, Kerstin A.; Jäger, Andreas; Bohn, Christian; Habermehl, Daniel; Zhang, Lanlan; Engelmann, Uwe; Bougatf, Nina; Bendl, Rolf; Debus, Jürgen; Combs, Stephanie E.

2013-03-01

To date, conducting retrospective clinical analyses is rather difficult and time consuming. Especially in radiation oncology, handling voluminous datasets from various information systems and different documentation styles efficiently is crucial for patient care and research. With the example of patients with pancreatic cancer treated with radio-chemotherapy, we performed a therapy evaluation by using analysis tools connected with a documentation system. A total number of 783 patients have been documented into a professional, web-based documentation system. Information about radiation therapy, diagnostic images and dose distributions have been imported. For patients with disease progression after neoadjuvant chemoradiation, we designed and established an analysis workflow. After automatic registration of the radiation plans with the follow-up images, the recurrence volumes are segmented manually. Based on these volumes the DVH (dose-volume histogram) statistic is calculated, followed by the determination of the dose applied to the region of recurrence. All results are stored in the database and included in statistical calculations. The main goal of using an automatic evaluation system is to reduce time and effort conducting clinical analyses, especially with large patient groups. We showed a first approach and use of some existing tools, however manual interaction is still necessary. Further steps need to be taken to enhance automation. Already, it has become apparent that the benefits of digital data management and analysis lie in the central storage of data and reusability of the results. Therefore, we intend to adapt the evaluation system to other types of tumors in radiation oncology.

Transport simulations of a density limit in radiation-dominated tokamak discharges: Profile effects

International Nuclear Information System (INIS)

Stotler, D.P.

1988-06-01

The density limit observed in tokamak experiments is thought to be due to a radiative collapse of the current channel. A transport code coupled with an MHD equilibrium routine is used to determine the detailed, self-consistent evolution of the plasma profiles in tokamak discharges with radiated power close to or equalling the input power. The present work is confined to ohmic discharges in steady state. It is found that the shape of the density profile can have a significant impact on the variation of the maximum electron density with plasma current. Analytic calculations confirm this result. 41 refs., 9 figs

Transport simulations of a density limit in radiation-dominated tokamak discharges: profile effects

International Nuclear Information System (INIS)

Stotler, D.P.

1988-01-01

The density limit observed in tokamak experiments is thought to be due to a radiative collapse of the current channel. A transport code coupled with a magnetohydrodynamic (MHD) equilibrium routine is used to determine the detailed, self-consistent evolution of the plasma profiles in tokamak discharges with radiated power close to or equaling the input power. The present work is confined to Ohmic discharges in steady state. It is found that the shape of the density profile can have a significant impact on the variation of the maximum electron density with plasma current. Analytic calculations confirm this result

Acceleration of a Monte Carlo radiation transport code

International Nuclear Information System (INIS)

Hochstedler, R.D.; Smith, L.M.

1996-01-01

Execution time for the Integrated TIGER Series (ITS) Monte Carlo radiation transport code has been reduced by careful re-coding of computationally intensive subroutines. Three test cases for the TIGER (1-D slab geometry), CYLTRAN (2-D cylindrical geometry), and ACCEPT (3-D arbitrary geometry) codes were identified and used to benchmark and profile program execution. Based upon these results, sixteen top time-consuming subroutines were examined and nine of them modified to accelerate computations with equivalent numerical output to the original. The results obtained via this study indicate that speedup factors of 1.90 for the TIGER code, 1.67 for the CYLTRAN code, and 1.11 for the ACCEPT code are achievable. copyright 1996 American Institute of Physics

Current status of radiation transport tools for proliferation and terrorism prevention

International Nuclear Information System (INIS)

Sale, K.E.

2004-01-01

Full text: We will present the current status and future plans for the set of calculational tools and databases developed and maintained at LLNL. The calculational tools include the Monte Carlo codes TART 1) and COG 2) as well as the deterministic code ARDRA 3) . In addition to these codes we use currently there is a major development effort for a new massively parallel transport code. An important part of the capability we're developing is a sophisticated user interface, based on a commercial 3-D modeling product, to improve the model development process. A major part of this user interface tool is being developed by Strela 4) under the Nuclear Cities Initiative. Strela has developed a hub-and-spoke technology for code input interconversions (between COG, TART and MCNP) and will produce the plug-ins that extend the capabilities of the 3-D modeler for use as a radiation transport input generator. The major advantages of this approach are the built-in user interface for 3-D modeling and the ability to read a large variety of CAD-file formats. In addition to supporting our current radiation transport codes and developing new capabilities we are working on some nuclear data needs for homeland security. These projects are carried out and the Lawrence Berkeley National Laboratory 88' cyclotron and at the Institute for Nuclear Research of the Nation Academy of Science of Ukraine under and STCU contract. Reference: 1. http://www.llnl.gov/cullen1/mc/htm; 2. http://www-phys.llnl.gov/N_Div/COG/ETR/ETR_9306.html; 3. http://www.llnl.gov/CASC/asciturb/talks/PPT-HTML.131596/tsld030.htm; 4. http://strela.snz.ru/

Wildfire particulate matter in Europe during summer 2003: meso-scale modeling of smoke emissions, transport and radiative effects

Directory of Open Access Journals (Sweden)

A. Hodzic

2007-08-01

Full Text Available The present study investigates effects of wildfire emissions on air quality in Europe during an intense fire season that occurred in summer 2003. A meso-scale chemistry transport model CHIMERE is used, together with ground based and satellite aerosol optical measurements, to assess the dispersion of fire emissions and to quantify the associated radiative effects. The model has been improved to take into account a MODIS-derived daily smoke emission inventory as well as the injection altitude of smoke particles. The simulated aerosol optical properties are put into a radiative transfer model to estimate (off-line the effects of smoke particles on photolysis rates and atmospheric radiative forcing. We have found that the simulated wildfires generated comparable amounts of primary aerosol pollutants (130 kTons of PM_2.5, fine particles to anthropogenic sources during August 2003, and caused significant changes in aerosol optical properties not only close to the fire source regions, but also over a large part of Europe as a result of the long-range transport of the smoke. Including these emissions into the model significantly improved its performance in simulating observed aerosol concentrations and optical properties. Quantitative comparison with MODIS and POLDER data during the major fire event (3–8 August 2003 showed the ability of the model to reproduce high aerosol optical thickness (AOT over Northern Europe caused by the advection of the smoke plume from the Portugal source region. Although there was a fairly good spatial agreement with satellite data (correlation coefficients ranging from 0.4 to 0.9, the temporal variability of AOT data at specific AERONET locations was not well captured by the model. Statistical analyses of model-simulated AOT data at AERONET ground stations showed a significant decrease in the model biases suggesting that wildfire emissions are responsible for a 30% enhancement in mean AOT values during the heat

Development of Parallel Computing Framework to Enhance Radiation Transport Code Capabilities for Rare Isotope Beam Facility Design

Energy Technology Data Exchange (ETDEWEB)

Kostin, Mikhail [Michigan State Univ., East Lansing, MI (United States); Mokhov, Nikolai [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Niita, Koji [Research Organization for Information Science and Technology, Ibaraki-ken (Japan)

2013-09-25

A parallel computing framework has been developed to use with general-purpose radiation transport codes. The framework was implemented as a C++ module that uses MPI for message passing. It is intended to be used with older radiation transport codes implemented in Fortran77, Fortran 90 or C. The module is significantly independent of radiation transport codes it can be used with, and is connected to the codes by means of a number of interface functions. The framework was developed and tested in conjunction with the MARS15 code. It is possible to use it with other codes such as PHITS, FLUKA and MCNP after certain adjustments. Besides the parallel computing functionality, the framework offers a checkpoint facility that allows restarting calculations with a saved checkpoint file. The checkpoint facility can be used in single process calculations as well as in the parallel regime. The framework corrects some of the known problems with the scheduling and load balancing found in the original implementations of the parallel computing functionality in MARS15 and PHITS. The framework can be used efficiently on homogeneous systems and networks of workstations, where the interference from the other users is possible.

Resonant electronic transport through a triple quantum-dot with Λ-type level structure under dual radiation fields

International Nuclear Information System (INIS)

Guan, Chun; Xing, Yunhui; Zhang, Chao; Ma, Zhongshui

2014-01-01

Due to quantum interference, light can transmit through dense atomic media, a phenomenon known as electromagnetically induced transparency (EIT). We propose that EIT is not limited to light transmission and there is an electronic analog where resonant transparency in charge transport in an opaque structure can be induced by electromagnetic radiation. A triple-quantum-dots system with Λ-type level structure is generally opaque due to the level in the center dot being significantly higher and therefore hopping from the left dot to the center dot is almost forbidden. We demonstrate that an electromagnetically induced electron transparency (EIET) in charge of transport can indeed occur in the Λ-type system. The direct evidence of EIET is that an electron can travel from the left dot to the right dot, while the center dot apparently becomes invisible. We analyze EIET and the related shot noise in both the zero and strong Coulomb blockade regimes. It is found that the EIET (position, height, and symmetry) can be tuned by several controllable parameters of the radiation fields, such as the Rabi frequencies and detuning frequencies. The result offers a transparency/opaque tuning technique in charge transport using interfering radiation fields

Modeling of laser radiation transport in powder beds with high-dispersive metal particles

Energy Technology Data Exchange (ETDEWEB)

Kharanzhevskiy, Evgeny, E-mail: eh@udsu.ru [Udmurt State University, 426034 Universitetskaya St., 1, Izhevsk (Russian Federation); Kostenkov, Sergey [Udmurt State University, 426034 Universitetskaya St., 1, Izhevsk (Russian Federation)

2014-02-15

Highlights: ► Transport of laser energy in dispersive powder beds was numerically simulated. ► The results of simulating are compared with physicals experiments. ► We established the dependence of the extinction coefficient from powder properties. ► A confirmation of a geometric optic approach for monodisperse powders was proposed. -- Abstract: Two-dimensional transfer of laser radiation in a high-dispersive powder heterogeneous media is numerically calculated. The size of particles is comparable with the wave length of laser radiation so the model takes into account all known physical effects that are occurred on the vacuum–metal surface interface. It is shown that in case of small particles size both morphology of powder particles and porosity of beds influence on absorptance by the solid phase and laser radiation penetrate deep into the area of geometric shadow. Intensity of laser radiation may be described as a function corresponded to the Beer–Lambert–Bouguer law.

Modeling of laser radiation transport in powder beds with high-dispersive metal particles

International Nuclear Information System (INIS)

Kharanzhevskiy, Evgeny; Kostenkov, Sergey

2014-01-01

Highlights: ► Transport of laser energy in dispersive powder beds was numerically simulated. ► The results of simulating are compared with physicals experiments. ► We established the dependence of the extinction coefficient from powder properties. ► A confirmation of a geometric optic approach for monodisperse powders was proposed. -- Abstract: Two-dimensional transfer of laser radiation in a high-dispersive powder heterogeneous media is numerically calculated. The size of particles is comparable with the wave length of laser radiation so the model takes into account all known physical effects that are occurred on the vacuum–metal surface interface. It is shown that in case of small particles size both morphology of powder particles and porosity of beds influence on absorptance by the solid phase and laser radiation penetrate deep into the area of geometric shadow. Intensity of laser radiation may be described as a function corresponded to the Beer–Lambert–Bouguer law

Continuous weighing of conveyor-transported materials based on gamma radiation conversion to electric current

International Nuclear Information System (INIS)

The principle is described of the continuous weighing of conveyer-transported materials applied in the food industry. The weighing technique is based on the measurement of the absorption of gamma radiation emitted by a source located behind the material to be scaled. (Z.M.)

Radiation protection program for transport of radiopharmaceutical and labelled compounds in Cuba

International Nuclear Information System (INIS)

Amador, Zayda H.; Perez, Saul; Ayra, Fernando E.; Torres, Mirta B.

2008-01-01

The Centre of Isotopes (CENTIS) is the main consignor and carrier of radioactive material in Cuba. The purpose of this work is to describe the Radiation Protection Program (RPP) implemented inside the Organization Quality Management System, to achieve and maintain an optimized standard of protection in the accomplishment of these functions. All those areas involving radiation exposures are considered (e.g. design of type A packages, packing, loading, handling, in-transit storage, road transport and inspection and maintenance of packaging). The quality assurance requirements for packaging components were established using a grading process. A material to absorb twice the volume of the liquid contents is tested and its water absorptivity, grammage and capillary rise were estimated. Categories and transport indexes for 56 packages of radiopharmaceuticals incorporating radioiodine, 32 P, 188 Re and 90 Y and technetium generators, are determined. Tests for demonstrating compliance with requirements for type A packages with liquid and solid radioactive content and for air transport are performed and documented. A numeric code for each package by consignee is registered and controlled in each step of the process and as a guarantee of its traceability. Safety and security of radioactive materials during storage in transit and transport are supervised. Training of workers trough periodic curses and emergency exercises is implementing. Individual Licensing of this staff is conducted by CENTIS and presented to the Cuban Regulatory Authority. The effective annual doses distributions are reported since 1996 to 2007. Occupational exposure is acceptably low and less than 6 mSv. It has not been reported any incident in about two thousand road shipments carried out. CENTIS' RPP has been under review, detailed appraisals and audits. The Certification of the management system by ISO 9001:2000 has been identified as a goal and a way for the continuous improvement. (author)

Electron transport in nanometer GaAs structure under radiation exposure

CERN Document Server

Demarina, N V

2002-01-01

One investigates into effect of neutron and proton irradiation on electron transport in nanometer GaAs structures. Mathematical model takes account of radiation defects via introduction of additional mechanisms od scattering of carriers at point defects and disordered regions. To investigate experimentally into volt-ampere and volt-farad characteristics one used a structure based on a field-effect transistor with the Schottky gate and a built-in channel. Calculation results of electron mobility, drift rate of electrons, time of energy relaxation and electron pulse are compared with the experimental data

A hybrid transport-diffusion method for Monte Carlo radiative-transfer simulations

International Nuclear Information System (INIS)

Densmore, Jeffery D.; Urbatsch, Todd J.; Evans, Thomas M.; Buksas, Michael W.

2007-01-01

Discrete Diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Monte Carlo particle-transport simulations in diffusive media. If standard Monte Carlo is used in such media, particle histories will consist of many small steps, resulting in a computationally expensive calculation. In DDMC, particles take discrete steps between spatial cells according to a discretized diffusion equation. Each discrete step replaces many small Monte Carlo steps, thus increasing the efficiency of the simulation. In addition, given that DDMC is based on a diffusion equation, it should produce accurate solutions if used judiciously. In practice, DDMC is combined with standard Monte Carlo to form a hybrid transport-diffusion method that can accurately simulate problems with both diffusive and non-diffusive regions. In this paper, we extend previously developed DDMC techniques in several ways that improve the accuracy and utility of DDMC for nonlinear, time-dependent, radiative-transfer calculations. The use of DDMC in these types of problems is advantageous since, due to the underlying linearizations, optically thick regions appear to be diffusive. First, we employ a diffusion equation that is discretized in space but is continuous in time. Not only is this methodology theoretically more accurate than temporally discretized DDMC techniques, but it also has the benefit that a particle's time is always known. Thus, there is no ambiguity regarding what time to assign a particle that leaves an optically thick region (where DDMC is used) and begins transporting by standard Monte Carlo in an optically thin region. Also, we treat the interface between optically thick and optically thin regions with an improved method, based on the asymptotic diffusion-limit boundary condition, that can produce accurate results regardless of the angular distribution of the incident Monte Carlo particles. Finally, we develop a technique for estimating radiation momentum deposition during the

Method of processing dismantled products of radiation-contaminated equipments and transportation container therefor

International Nuclear Information System (INIS)

Komura, Shiro; Heki, Hideaki.

1991-01-01

In a method of decontaminating dismantled products of radiation-contaminated equipments removed at nuclear power facilities and classifying the dismantled products depending on their remaining radioactivity levels measured at a processing facility, the dismantled products are contained in a transportation container, to which decontamination liquids are injected and they are transferred to the processing facility. The decontaminated liquid wastes are drained from the transportation container, the dismantled products are washed while being contained in the transportation container as they are. Then, they are transferred to a step for measuring their remaining radioactivity level. This can shorten the time from the containment of the dismantled products to the transportation container to the completion of the decontamination, to improve the efficiency for the decontamination processing. Further, by separately containing the dismantled products on every kind of materials to respective containers, the processing time can be appropriately controlled respectively even if the dissolving efficiency to the decontamination liquids is different depending on the materials. (T.M.)

Legal and governmental infrastructure for nuclear, radiation, radioactive waste and transport safety. Safety requirements

International Nuclear Information System (INIS)

2000-01-01

This publication establishes requirements for legal and governmental responsibilities in respect of the safety of nuclear facilities, the safe use of sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material. Thus, it covers development of the legal framework for establishing a regulatory body and other actions to achieve effective regulatory control of facilities and activities. Other responsibilities are also covered, such as those for developing the necessary support for safety, involvement in securing third party liability and emergency preparedness

Legal and governmental infrastructure for nuclear, radiation, radioactive waste and transport safety. Safety requirements

International Nuclear Information System (INIS)

2004-01-01

This publication establishes requirements for legal and governmental responsibilities in respect of the safety of nuclear facilities, the safe use of sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material. Thus, it covers development of the legal framework for establishing a regulatory body and other actions to achieve effective regulatory control of facilities and activities. Other responsibilities are also covered, such as those for developing the necessary support for safety, involvement in securing third party liability and emergency preparedness

ATR, Radiation Transport Models in Atmosphere at Various Altitudes

International Nuclear Information System (INIS)

1981-01-01

1 - Description of problem or function: ATR is a user-oriented code for calculating quickly and simply radiation environment problems at all altitudes in the atmosphere. The code is based on parametric models of a comprehensive data base of air transport results which were generated using discrete ordinates transport techniques for infinite homogeneous air. The effects of air-ground interface and non-uniform air density are treated as perturbation corrections on homogeneous air results. ATR includes parametric models for neutrons and secondary gamma rays as a function of space, energy and source- target angle out to angles of 550 g/cm 2 of air. ATR contains parameterizations of infinite medium air transport of neutrons and secondary gamma rays and correction factors for the air-ground interface and high altitude exponential air. It responds to a series of user-oriented commands which specify the source, geometry and print options to output a variety of useful air transport information, including energy-angle dependent fluence, dose, current, and isodose ranges. 2 - Method of solution: The version 3 differs from earlier versions in that version 3 contains the parameterization of the new neutron and secondary gamma rays data base that was calculated using the latest DNA approved cross sections for air. Other improvements to the ATR code include: parameterization and inclusion into ATR of new air- over-ground correction factors, low energy x-rays calculations, new fission source, and new convenience options. 3 - Restrictions on the complexity of the problem: ATR takes approximately 36,000 decimal words of storage. This can be lessened by overlaying different parts of the code

Evaluation of the computer code system RADHEAT-V4 by analysing benchmark problems on radiation shielding

International Nuclear Information System (INIS)

Sakamoto, Yukio; Naito, Yoshitaka

1990-11-01

A computer code system RADHEAT-V4 has been developed for safety evaluation on radiation shielding of nuclear fuel facilities. To evaluate the performance of the code system, 18 benchmark problem were selected and analysed. Evaluated radiations are neutron and gamma-ray. Benchmark problems consist of penetration, streaming and skyshine. The computed results show more accurate than those by the Sn codes ANISN and DOT3.5 or the Monte Carlo code MORSE. Big core memory and many times I/O are, however, required for RADHEAT-V4. (author)

Radiation doses from the transport of radioactive waste to a future repository in Denmark. A model study

International Nuclear Information System (INIS)

2011-05-01

The radiation doses modelled for transport of radioactive waste to a future repository in Denmark, demonstrates that the risk associated with road and sea transport should not limit the future selection of a location of the repository. From a safety perspective both road and sea transport seem to be feasible modes of transport. Although the modelling in most cases is performed conservatively, the modelled doses suggest that both transport methods can be carried out well within the national dose limits. Additionally, the dose levels associated with the modelled accident scenarios are low and the scenarios are thus found to be acceptable taken the related probabilities into account. (LN)

Radiation doses from the transport of radioactive waste to a future repository in Denmark. A model study

Energy Technology Data Exchange (ETDEWEB)

2011-05-15

The radiation doses modelled for transport of radioactive waste to a future repository in Denmark, demonstrates that the risk associated with road and sea transport should not limit the future selection of a location of the repository. From a safety perspective both road and sea transport seem to be feasible modes of transport. Although the modelling in most cases is performed conservatively, the modelled doses suggest that both transport methods can be carried out well within the national dose limits. Additionally, the dose levels associated with the modelled accident scenarios are low and the scenarios are thus found to be acceptable taken the related probabilities into account. (LN)

PBMC: Pre-conditioned Backward Monte Carlo code for radiative transport in planetary atmospheres

Science.gov (United States)

García Muñoz, A.; Mills, F. P.

2017-08-01

PBMC (Pre-Conditioned Backward Monte Carlo) solves the vector Radiative Transport Equation (vRTE) and can be applied to planetary atmospheres irradiated from above. The code builds the solution by simulating the photon trajectories from the detector towards the radiation source, i.e. in the reverse order of the actual photon displacements. In accounting for the polarization in the sampling of photon propagation directions and pre-conditioning the scattering matrix with information from the scattering matrices of prior (in the BMC integration order) photon collisions, PBMC avoids the unstable and biased solutions of classical BMC algorithms for conservative, optically-thick, strongly-polarizing media such as Rayleigh atmospheres.

Estimation of edge electron temperature profiles via forward modelling of the electron cyclotron radiation transport at ASDEX Upgrade

International Nuclear Information System (INIS)

Rathgeber, S K; Barrera, L; Eich, T; Fischer, R; Suttrop, W; Wolfrum, E; Nold, B; Willensdorfer, M

2013-01-01

We present a method to obtain reliable edge profiles of the electron temperature by forward modelling of the electron cyclotron radiation transport. While for the core of ASDEX Upgrade plasmas, straightforward analysis of electron cyclotron intensity measurements based on the optically thick plasma approximation is usually justified, reasonable analysis of the steep and optically thin plasma edge needs to consider broadened emission and absorption profiles and radiation transport processes. This is carried out in the framework of integrated data analysis which applies Bayesian probability theory for joint analysis of the electron density and temperature with data of different interdependent and complementary diagnostics. By this means, electron cyclotron radiation intensity delivers highly spatially resolved electron temperature data for the plasma edge. In H-mode, the edge gradient of the electron temperature can be several times higher than the one of the radiation temperature. Furthermore, we are able to reproduce the ‘shine-through’ peak—the observation of increased radiation temperatures at frequencies resonant in the optically thin scrape-off layer. This phenomenon is caused by strongly down-shifted radiation of Maxwellian tail electrons located in the H-mode edge region and, therefore, contains valuable information about the electron temperature edge gradient. (paper)

HZETRN radiation transport validation using balloon-based experimental data

Science.gov (United States)

Warner, James E.; Norman, Ryan B.; Blattnig, Steve R.

2018-05-01

The deterministic radiation transport code HZETRN (High charge (Z) and Energy TRaNsport) was developed by NASA to study the effects of cosmic radiation on astronauts and instrumentation shielded by various materials. This work presents an analysis of computed differential flux from HZETRN compared with measurement data from three balloon-based experiments over a range of atmospheric depths, particle types, and energies. Model uncertainties were quantified using an interval-based validation metric that takes into account measurement uncertainty both in the flux and the energy at which it was measured. Average uncertainty metrics were computed for the entire dataset as well as subsets of the measurements (by experiment, particle type, energy, etc.) to reveal any specific trends of systematic over- or under-prediction by HZETRN. The distribution of individual model uncertainties was also investigated to study the range and dispersion of errors beyond just single scalar and interval metrics. The differential fluxes from HZETRN were generally well-correlated with balloon-based measurements; the median relative model difference across the entire dataset was determined to be 30%. The distribution of model uncertainties, however, revealed that the range of errors was relatively broad, with approximately 30% of the uncertainties exceeding ± 40%. The distribution also indicated that HZETRN systematically under-predicts the measurement dataset as a whole, with approximately 80% of the relative uncertainties having negative values. Instances of systematic bias for subsets of the data were also observed, including a significant underestimation of alpha particles and protons for energies below 2.5 GeV/u. Muons were found to be systematically over-predicted at atmospheric depths deeper than 50 g/cm2 but under-predicted for shallower depths. Furthermore, a systematic under-prediction of alpha particles and protons was observed below the geomagnetic cutoff, suggesting that

The use of symbolic computation in radiative, energy, and neutron transport calculations. Final report

International Nuclear Information System (INIS)

Frankel, J.I.

1997-01-01

This investigation used sysmbolic manipulation in developing analytical methods and general computational strategies for solving both linear and nonlinear, regular and singular integral and integro-differential equations which appear in radiative and mixed-mode energy transport. Contained in this report are seven papers which present the technical results as individual modules

Assessment of health risks brought about by transportation of spent fuel

International Nuclear Information System (INIS)

Suolanen, V.; Lautkaski, R.; Rossi, J.

1999-03-01

In the study health risks caused by transportation of spent fuel from Olkiluoto and from Loviisa NPP's to the planned disposal site have been evaluated. The Olkiluoto NPP is owned by Teollisuuden Voima Oy (TVO) and the Loviisa NPP, situated at Haestholmen, by Fortum Power and Heat Oy. According to the base scenario of 40 years use of the current NPP's the total amount of spent fuel will be 1840 tU (TVO) and 860 tU (Fortum). Annually, 110 tU on the average and at most 250 tU will be transported to the disposal site. The considered transportation routes are from Olkiluoto to Haestholmen, from Olkiluoto to Kivetty, from Olkiluoto to Romuvaara, from Haestholmen to Olkiluoto, from Haestholmen to Kivetty and from Haestholmen to Romuvaara. The considered transportation modes are truck, rail or ship, or combinations of these modes. Each transportation route has been divided into homogenised sequences with respect to population density and/or route type. Total amount of analysed route options were 40, some route sequences are overlapping. Radiation exposures to the population along the routes have been calculated in normal, incident and accident situations during transportation. Occupational radiation doses to the personnel have been estimated for normal transportation only. The consequences of normal transportation have been evaluated based on RADTRAN-model, developed by the Sandia National Laboratories. As incidents, stopping of spent fuel transportation for an exceptionally long period of time, and in another case contamination of outer surface of spent fuel cask have been considered. Expected collective doses and health risks of transportation accidents connected to the routes have been calculated with RADTRAN-model. Single hypothetical transport accidents with pessimistic release assumptions have been further analysed in more detail with the ARANO-model, developed by VTT (Technical Research Centre of Finland). (orig.)

SQA of finite element method (FEM) codes used for analyses of pit storage/transport packages

Energy Technology Data Exchange (ETDEWEB)

Russel, E. [Lawrence Livermore National Lab., CA (United States)

1997-11-01

This report contains viewgraphs on the software quality assurance of finite element method codes used for analyses of pit storage and transport projects. This methodology utilizes the ISO 9000-3: Guideline for application of 9001 to the development, supply, and maintenance of software, for establishing well-defined software engineering processes to consistently maintain high quality management approaches.

2D numerical comparison between S{sub n} and M{sub 1} radiation transport methods

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Matthias [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, calle Jose Gutierrez Abascal 2, 28006 Madrid (Spain)], E-mail: matthias@din.upm.es; Garcia-Fernandez, Carlos [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, calle Jose Gutierrez Abascal 2, 28006 Madrid (Spain)], E-mail: carlos@din.upm.es; Velarde, Pedro [Instituto de Fusion Nuclear, Universidad Politecnica de Madrid, calle Jose Gutierrez Abascal 2, 28006 Madrid (Spain)], E-mail: velarde@din.upm.es

2009-07-15

In this article we study the accuracy of the M{sub 1} method to solve some relevant radiation transport problems in 2D. We compare two radiation models (S{sub n} and M{sub 1}) with analytical and numerical tests to highlight the strengths and limitations of each method. These methods give comparable results except when sharp geometry effects are present. We have used these methods in a test that mimics, without fluid motion or electron heat conduction, the cone-target interaction relevant to inertial confinement fusion physics. In this case, we show that S{sub n} and M{sub 1} models agree with a quite good accuracy but shows differences in the temperature profiles and heating times inside the target. These results point out that M{sub 1} is a possible alternative candidate for 3D simulations, where full energy transport methods are extremely computer time consuming.

A Monte Carlo Code for Relativistic Radiation Transport Around Kerr Black Holes

Science.gov (United States)

Schnittman, Jeremy David; Krolik, Julian H.

2013-01-01

We present a new code for radiation transport around Kerr black holes, including arbitrary emission and absorption mechanisms, as well as electron scattering and polarization. The code is particularly useful for analyzing accretion flows made up of optically thick disks and optically thin coronae. We give a detailed description of the methods employed in the code and also present results from a number of numerical tests to assess its accuracy and convergence.

A comparison of radiation doses and risks between spent fuel transport/storage and selected non-nuclear activities

International Nuclear Information System (INIS)

Pennington, C.W.

2003-01-01

Spent fuel transport and storage have achieved an exemplary safety record over four decades within both the United States (US) and the global community at large. This paper offers an assessment demonstrating the safety of spent fuel transport and storage packagings relative to currently accepted but unregulated non-nuclear activities and practices within society. Over the last quarter of a century, several spent fuel transport and storage packaging test programmes have produced data that allow calculation of potential releases and population doses resulting from a terrorist attack. The US Department of Energy (DOE) has used this information to develop projected worst-case, low probability population exposures as part of the Final Environmental Impact Statement (FEIS) for the Yucca Mountain repository. The paper discusses potential population exposures from these packagings based on analysis and testing under beyond-design-basis (BDB) events, including missile attacks, and then defines and defends an acceptance criterion for the bounding outcomes of these events, based upon current accepted activities within society that produce high radiation doses to the general public. These activities involve unregulated technologies and practices within society that yield population doses significantly exceeding those that would result from such hypothetical and highly improbable events as a terrorist missile attack on a spent fuel transport or storage packaging. In particular, technologically enhanced natural radiation (TENR) exposures from building materials, farming, and masonry construction are highlighted. Recent landmark work by the US National Academy of Sciences (NAS) and by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) are cited in support of this assessment, along with work from the US Environmental Protection Agency (EPA). From this compelling evidence, it is concluded that spent fuel transport and storage represent a low

The application of fluid structure interaction techniques within finite element analyses of water-filled transport flasks

International Nuclear Information System (INIS)

Smith, C.; Stojko, S.

2004-01-01

Historically, Finite Element (FE) analyses of water-filled transport flasks and their payloads have been carried out assuming a dry environment, mainly due to a lack of robust Fluid Structure Interaction (FSI) modelling techniques. Also it has been accepted within the RAM transport industry that the presence of water would improve the impact withstand capability of dropped payloads within containers. In recent years the FE community has seen significant progress and improvement in FSI techniques. These methods have been utilised to investigate the effects of a wet environment on payload behaviour for the regulatory drop test within a recent transport licence renewal application. Fluid flow and pressure vary significantly during a wet impact and the effects on the contents become complex when water is incorporated into the flask analyses. Modelling a fluid environment within the entire flask is considered impractical; hence a good understanding of the FSI techniques and assumptions regarding fluid boundaries is required in order to create a representative FSI model. Therefore, a Verification and Validation (V and V) exercise was undertaken to underpin the FSI techniques eventually utilised. A number of problems of varying complexity have been identified to test the FSI capabilities of the explicit code LS-DYNA, which is used in the extant dry container impact analyses. RADIOSS explicit code has been used for comparison, to provide further confidence in LS-DYNA predictions. Various methods of modelling fluid are tested, and the relative advantages and limitations of each method and FSI coupling approaches are discussed. Results from the V and V problems examined provided sufficient confidence that FSI effects within containers can be accurately modelled

Radiation induced low-energy electron transport in a tissue environment

International Nuclear Information System (INIS)

Toburen, L.H.; Dingfelder, M.; Ozturk, N.; Christou, C.; Shinpaugh, J.L.; Friedland, W.; Wilson, W.E.; Paretzke, H.G.

2003-01-01

Monte Carlo (MC) track simulation codes are used extensively in radiobiology to quantify the spatial distributions of interactions initiated by the absorption of ionizing radiation. The spatial patterns of ionization and excitation are instrumental for assessing the formation of damage clusters in DNA and chromosomes leading to such biologic endpoints as cellular transformation and mutation. The MC codes rely on an extensive database of elastic and inelastic scattering cross sections to follow the production and slowing of secondary electrons. Because of inherent uncertainties in this database we are exploring the sensitivity of MC results to the details of the cross sections used with emphasis on low-energy electrons, i.e., track ends, that are anticipated to play a dominant role in damage cluster formation. Simulations of electron transport using gas or liquid based interaction cross sections illustrate substantial difference in the spectra of electrons with energies less than about 50 eV. In addition, the electron yields from MC simulations appear to be nearly a factor of five larger than our recent measurements of electron transport spectra in water (ice) at electron energies of about 10 eV. Examples of the changes in electron transport spectra for variations in the electron scattering cross sections used for the MC calculations will be illustrated and compared with an evolving database of measured spectra of electrons from ion induced secondary electron transport in thin foils. These measurements provide guidance for assessment of elastic and elastic cross sections appropriate to condensed phase transport. This work is supported in part by the U.S. Department of Energy, Grant No. DE-FG02-01ER-63233; the National Cancer Institute, Grant No. 1R01CA93351-01A1; and the European Community under Contract No. FIGH-CT-1999-00005

Reactive transport modelling of a heating and radiation experiment in the Boom clay (Belgium)

International Nuclear Information System (INIS)

Montenegro, L.; Samper, J.; Delgado, J.

2003-01-01

Most countries around the world consider Deep Geological Repositories (DGR) as the most safe option for the final disposal of high level radioactive waste (HLW). DGR is based on adopting a system of multiple barriers between the HLW and the biosphere. Underground laboratories provide information about the behaviour of these barriers at real conditions. Here we present a reactive transport model for the CERBERUS experiment performed at the HADES underground laboratory at Mol (Belgium) in order to characterize the thermal (T), hydrodynamic (H) and geochemical (G) behaviour of the Boon clay. This experiment is unique because it addresses the combined effect of heat and radiation produced by the storage of HLW in a DGR. Reactive transport models which are solved with CORE, are used to perform quantitative predictions of Boom clay thermo-hydro-geochemical (THG) behaviour. Numerical results indicate that heat and radiation cause a slight oxidation near of the radioactive source, pyrite dissolution, a pH decrease and slight changes in the pore water chemical composition of the Boom clay. (Author) 33 refs

An investigation of fission models for high-energy radiation transport calculations

International Nuclear Information System (INIS)

Armstrong, T.W.; Cloth, P.; Filges, D.; Neef, R.D.

1983-07-01

An investigation of high-energy fission models for use in the HETC code has been made. The validation work has been directed checking the accuracy of the high-energy radiation transport computer code HETC to investigate the appropriate model for routine calculations, particularly for spallation neutron source applications. Model calculations are given in terms of neutron production, fission fragment energy release, and residual nuclei production for high-energy protons incident on thin uranium targets. The effect of the fission models on neutron production from thick uranium targets is also shown. (orig.)

On the requirement for remodelling the spent nuclear fuel transportation casks for research reactors. A review of the drop impact analyses of JRC-80Y-20T

International Nuclear Information System (INIS)

2005-07-01

The Japan Atomic Energy Research Institute (JAERI) constructed two stainless steel transportation casks, JRC-80Y-20T, for spent nuclear fuels of research reactors and had utilized them for transportation since 1981. A modification of the design was applied to the United States of America (USA) for transportation of silicide fuels. Additional analyses employing the impact analysis code LS-DYNA that was often used for safety analysis were submitted by the JAERI to the USA in 2003 to show integrity of the packages; the casks were still not approved, because inelastic deformation was occurred on the surface of the lid touching to the body. To resolve this problem on design approval of transportation casks, a review group was formed in June 2004. The group examined the impact analyses by reviewing the input data and performing the sensitivity analyses. As the drop impact analyses were found to be practically reasonable, it was concluded that the approval of the USA for the transportation casks could not be obtained just by revising the analyses; therefore, remodelling the casks is required. (author)

Public radiation exposure due to radon transport from a uranium mine

International Nuclear Information System (INIS)

Akber, R.A.; Johnston, A.; Pfitzner, J.

1992-01-01

Radon and radon daughter concentrations at locations several kilometres away from a uranium mine are due both to the background sources and the mine-related sources. The contribution of these two types of sources should be distinguished because the authorised limits on public radiation dose apply only to the mine-related sources. Such a distinction can be achieved by measuring radon and radon daughter concentration in the wind sectors containing only the background sources and those in the wind sectors containing both the background and the mine-related sources. This approach has been used to make estimates of public radiation dose due to radon transport from the Ranger Uranium Mine in Australia. The residential town of Jabiru, the non-residential working town of Jabiru East, and the aboriginal camp sites in the vicinity of the mine were considered. The results indicate that, for the groups of population considered, the annual mine-related dose varies between 0.04 and 0.2 mSv. (author)

Transport and stability analyses supporting disruption prediction in high beta KSTAR plasmas

Science.gov (United States)

Ahn, J.-H.; Sabbagh, S. A.; Park, Y. S.; Berkery, J. W.; Jiang, Y.; Riquezes, J.; Lee, H. H.; Terzolo, L.; Scott, S. D.; Wang, Z.; Glasser, A. H.

2017-10-01

KSTAR plasmas have reached high stability parameters in dedicated experiments, with normalized beta βN exceeding 4.3 at relatively low plasma internal inductance li (βN/li>6). Transport and stability analyses have begun on these plasmas to best understand a disruption-free path toward the design target of βN = 5 while aiming to maximize the non-inductive fraction of these plasmas. Initial analysis using the TRANSP code indicates that the non-inductive current fraction in these plasmas has exceeded 50 percent. The advent of KSTAR kinetic equilibrium reconstructions now allows more accurate computation of the MHD stability of these plasmas. Attention is placed on code validation of mode stability using the PEST-3 and resistive DCON codes. Initial evaluation of these analyses for disruption prediction is made using the disruption event characterization and forecasting (DECAF) code. The present global mode kinetic stability model in DECAF developed for low aspect ratio plasmas is evaluated to determine modifications required for successful disruption prediction of KSTAR plasmas. Work supported by U.S. DoE under contract DE-SC0016614.

PATRAM '83: 7th international symposium on packaging and transportation of radioactive materials

International Nuclear Information System (INIS)

1983-01-01

Papers were presented at the following sessions: international regulations; materials, fracture toughness of ferritic steels; risk analysis techniques; storage in packagings; packaging design considerations; monolithic cast iron casks; risk analysis; facility/transportation system interface; research and development programs; UF 6 packagings; national regulations; transportation operations and traffic; containment, seals, and leakage; radiation risk experience; emergency response; structural modeling and testing; transportation system planning; institutional issues and public response; packaging systems; thermal analysis and testing; systems analysis; structural analyses; quality assurance; packaging and transportation systems; physical protection; criticality and shielding; transportation operations and experience; standards; shock absorber technology; and information and training for regulatory compliance. Individual summaries are title listed

RADICAL. Radiation information centre with analysing logic

International Nuclear Information System (INIS)

Rantanen, H.

1998-01-01

in an emergency, the production of data is overwhelming and the need of accurate and up-to-date information is essential. In Finland a new system (RADICAL) has been developed in order to automatically collect and maintain an overall view of the radiation situation and to facilitate the analysis of the consequences of any radiation incident. The project was started in the beginning of 1992 and the system was operational in summer 1994. The main objectives of the development process and how they are being fulfilled with the RADICAL system are discussed. (author)

Transport of infrared radiation in cuboidal clouds

Science.gov (United States)

Harshvardhan, MR.; Weinman, J. A.; Davies, R.

1981-01-01

The transport of infrared radiation in a single cuboidal cloud is modeled using a variable azimuth two-stream approximation. Computations are made at 10 microns for a Deirmendjian (1969) C-1 water cloud where the single scattering albedo is equal to 0.638 and the asymmetry parameter is 0.865. The results indicate that the emittance of the top face of the model cloud is always less than that for a plane parallel cloud of the same optical depth. The hemispheric flux escaping from the cloud top possesses a gradient from the center to the edges which are warmer when the cloud is over warmer ground. Cooling rate calculations in the 8-13.6 micron region demonstrate that there is cooling out of the sides of the cloud at all levels even when there is heating of the core from the ground below. The radiances exiting from model cuboidal clouds are computed by path integration over the source function obtained with the two-stream approximation. Results indicate that the brightness temperature measured from finite clouds will overestimate the cloud-top temperature.

Many-integrated core (MIC) technology for accelerating Monte Carlo simulation of radiation transport: A study based on the code DPM

Science.gov (United States)

Rodriguez, M.; Brualla, L.

2018-04-01

Monte Carlo simulation of radiation transport is computationally demanding to obtain reasonably low statistical uncertainties of the estimated quantities. Therefore, it can benefit in a large extent from high-performance computing. This work is aimed at assessing the performance of the first generation of the many-integrated core architecture (MIC) Xeon Phi coprocessor with respect to that of a CPU consisting of a double 12-core Xeon processor in Monte Carlo simulation of coupled electron-photonshowers. The comparison was made twofold, first, through a suite of basic tests including parallel versions of the random number generators Mersenne Twister and a modified implementation of RANECU. These tests were addressed to establish a baseline comparison between both devices. Secondly, through the p DPM code developed in this work. p DPM is a parallel version of the Dose Planning Method (DPM) program for fast Monte Carlo simulation of radiation transport in voxelized geometries. A variety of techniques addressed to obtain a large scalability on the Xeon Phi were implemented in p DPM. Maximum scalabilities of 84 . 2 × and 107 . 5 × were obtained in the Xeon Phi for simulations of electron and photon beams, respectively. Nevertheless, in none of the tests involving radiation transport the Xeon Phi performed better than the CPU. The disadvantage of the Xeon Phi with respect to the CPU owes to the low performance of the single core of the former. A single core of the Xeon Phi was more than 10 times less efficient than a single core of the CPU for all radiation transport simulations.

Description of a neutron field perturbed by a probe using coupled Monte Carlo and discrete ordinates radiation transport calculations

International Nuclear Information System (INIS)

Zazula, J.M.

1984-01-01

This work concerns calculation of a neutron response, caused by a neutron field perturbed by materials surrounding the source or the detector. Solution of a problem is obtained using coupling of the Monte Carlo radiation transport computation for the perturbed region and the discrete ordinates transport computation for the unperturbed system. (author). 62 refs

The impact of coherent synchrotron radiation on the beam transport of short bunches

International Nuclear Information System (INIS)

Li, R.

1999-01-01

Designs for next-generation accelerator, such as future linear colliders and short-wavelength FEL drivers, require beams of short (mm-length or smaller) bunches and high charge (nC-regime). As such a high charge microbunch traverses magnetic bends, the curvature effect on the bunch self-interaction, by way of coherent synchrotron radiation (CSR) and space charge force, may cause serious emittance degradation. This impact of CSR on the beam transport of short bunches has raised significant concern in the design of future machines and led to extensive investigations. This paper reviews some of the recent progress in the understanding of the CSR effect, presents analysis of and computational work on the CSR impact on short bunch transport, and addresses remaining issues

Regulatory aspects of the transport of high radiation level and alpha waste in France

International Nuclear Information System (INIS)

Devillers, C.; Grenier, M.; Lombard, J.; Mathieu, F.

1993-01-01

The introduction of the 10 mSv.h -1 at 3 m limit for LSA unshielded material makes it impossible to transport, as LSA material, the highest radiation level wastes from EdF PWR's operations. At present, the EdF's waste blocks can be transported as LSA III material by special arrangement. A new package design, equivalent to a Type B package, will be available for their transport before the end of the year 1995. It consists of a re-usable steel cylinder over-packing each block. Compliance of this package model with transport safety requirements will be demonstrated by taking into account the non-dispersability, as LSA III material, of the irradiating waste. A two-step approach has been accepted by the French Competent Authority for the transport of these wastes: (1) a specific ISO 20 container, thermally insulated, can be used by special arrangement for the transport of LSA combustible material having a total activity per conveyance higher than 100 A2. Furthermore, additional safety measures have to be implemented for these consignments. (2) After the end of 1995, a Type B package must be used for activity contents per conveyance higher than 100 A2. A specific 20' ISO container, complying with Type B requirements, is being developed for that purpose. (author)

Statistical analyses of the data on occupational radiation expousure at JPDR

International Nuclear Information System (INIS)

Kato, Shohei; Anazawa, Yutaka; Matsuno, Kenji; Furuta, Toshishiro; Akiyama, Isamu

1980-01-01

In the statistical analyses of the data on occupational radiation exposure at JPDR, statistical features were obtained as follows. (1) The individual doses followed log-normal distribution. (2) In the distribution of doses from one job in controlled area, the logarithm of the mean (μ) depended on the exposure rate (γ(mR/h)), and the σ correlated to the nature of the job and normally distributed. These relations were as follows. μ = 0.48 ln r-0.24, σ = 1.2 +- 0.58 (3) For the data containing different groups, the distribution of doses showed a polygonal line on the log-normal probability paper. (4) Under the dose limitation, the distribution of the doses showed asymptotic curve along the limit on the log-normal probability paper. (author)

Charge transport properties of CdMnTe radiation detectors

Energy Technology Data Exchange (ETDEWEB)

Kim K.; Rafiel, R.; Boardman, M.; Reinhard, I.; Sarbutt, A.; Watt, G.; Watt, C.; Uxa, S.; Prokopovich, D.A.; Belas, E.; Bolotnikov, A.E.; James, R.B.

2012-04-11

Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe)radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading chargecollection is reduced with increasing values of bias voltage. The electron transit time was determined from time of flight measurements. From the dependence of drift velocity on applied electric field the electron mobility was found to be n = (718 55) cm2/Vs at room temperature.

Large enhancement of highly energetic electrons in the outer radiation belt and its transport into the inner radiation belt inferred from MDS-1 satellite observations

Science.gov (United States)

Obara, T.; Matsumoto, H.

2016-03-01

We have examined a large increase of relativistic electrons in the outer radiation belt and its penetration into the inner radiation belt over slot region using the MDS-1 satellite observations. Result of analyses demonstrates that a large increase took place in the spring and autumn seasons, and we have newly confirmed that the penetration of outer belt electrons to the inner radiation zone took place during the big magnetic storms by examining a pitch angle distribution of the penetrating electrons.

A Monte Carlo transport code study of the space radiation environment using FLUKA and ROOT

CERN Document Server

Wilson, T; Carminati, F; Brun, R; Ferrari, A; Sala, P; Empl, A; MacGibbon, J

2001-01-01

We report on the progress of a current study aimed at developing a state-of-the-art Monte-Carlo computer simulation of the space radiation environment using advanced computer software techniques recently available at CERN, the European Laboratory for Particle Physics in Geneva, Switzerland. By taking the next-generation computer software appearing at CERN and adapting it to known problems in the implementation of space exploration strategies, this research is identifying changes necessary to bring these two advanced technologies together. The radiation transport tool being developed is tailored to the problem of taking measured space radiation fluxes impinging on the geometry of any particular spacecraft or planetary habitat and simulating the evolution of that flux through an accurate model of the spacecraft material. The simulation uses the latest known results in low-energy and high-energy physics. The output is a prediction of the detailed nature of the radiation environment experienced in space as well a...

Radiation safety and gynaecological brachytherapy

International Nuclear Information System (INIS)

Crawford, L.

1985-01-01

In 1983, the Radiation Control Section of the South Australian Health Commission conducted an investigation into radiation safety practices in gynaecological brachytherapy. Part of the investigation included a study of the transportation of radioactive sources between hospitals. Several deficiences in radiation safety were found in the way these sources were being transported. New transport regulations came into force in South Australia in July 1984 and since then there have been many changes in the transportation procedure

Vertical Structure of Radiation-pressure-dominated Thin Disks: Link between Vertical Advection and Convective Stability

International Nuclear Information System (INIS)

Gong, Hong-Yu; Gu, Wei-Min

2017-01-01

In the classic picture of standard thin accretion disks, viscous heating is balanced by radiative cooling through the diffusion process, and the radiation-pressure-dominated inner disk suffers convective instability. However, recent simulations have shown that, owing to the magnetic buoyancy, the vertical advection process can significantly contribute to energy transport. In addition, in comparing the simulation results with the local convective stability criterion, no convective instability has been found. In this work, following on from simulations, we revisit the vertical structure of radiation-pressure-dominated thin disks and include the vertical advection process. Our study indicates a link between the additional energy transport and the convectively stable property. Thus, the vertical advection not only significantly contributes to the energy transport, but it also plays an important role in making the disk convectively stable. Our analyses may help to explain the discrepancy between classic theory and simulations on standard thin disks.

TIERCE: A code system for particles and radiation transport in thick targets

Energy Technology Data Exchange (ETDEWEB)

Bersillon, O.; Bauge, E.; Borne, F.; Clergeau, J.F.; Collin, M.; Cotten, D.; Delaroche, J.P.; Duarte, H.; Flament, J.L.; Girod, M.; Gosselin, G.; Granier, T.; Hilaire, S.; Morel, P.; Perrier, R.; Romain, P.; Roux, L. [CEA, Bruyeres-le-Chatel (France). Service de Physique Nucleaire

1997-09-01

Over the last few years, a great effort at Bruyeres-le-Chatel has been the development of the TIERCE code system for the transport of particles and radiations in complex geometry. The comparison of calculated results with experimental data, either microscopic (double differential spectra, residual nuclide yield...) or macroscopic (energy deposition, neutron leakage...), shows the need to improve the nuclear reaction models used. We present some new developments concerning data required for the evaporation model in the framework of a microscopic approach. 22 refs., 6 figs.

Statistical analyses of local transport coefficients in Ohmic ASDEX discharges

International Nuclear Information System (INIS)

Simmet, E.; Stroth, U.; Wagner, F.; Fahrbach, H.U.; Herrmann, W.; Kardaun, O.J.W.F.; Mayer, H.M.

1991-01-01

Tokamak energy transport is still an unsolved problem. Many theoretical models have been developed, which try to explain the anomalous high energy-transport coefficients. Up to now these models have been applied to global plasma parameters. A comparison of transport coefficients with global confinement time is only conclusive if the transport is dominated by one process across the plasma diameter. This, however, is not the case in most Ohmic confinement regimes, where at least three different transport mechanisms play an important role. Sawtooth activity leads to an increase in energy transport in the plasma centre. In the intermediate region turbulent transport is expected. Candidates here are drift waves and resistive fluid turbulences. At the edge, ballooning modes or rippling modes could dominate the transport. For the intermediate region, one can deduce theoretical scaling laws for τ E from turbulent theories. Predicted scalings reproduce the experimentally found density dependence of τ E in the linear Ohmic confinement regime (LOC) and the saturated regime (SOC), but they do not show the correct dependence on the isotope mass. The relevance of these transport theories can only be tested in comparing them to experimental local transport coefficients. To this purpose we have performed transport calculations on more than a hundred Ohmic ASDEX discharges. By Principal Component Analysis we determine the dimensionless components which dominate the transport coefficients and we compare the results to the predictions of various theories. (author) 6 refs., 2 figs., 1 tab

Development of radiation dose assessment system for radiation accident (RADARAC)

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Shigemori, Yuji; Seki, Akiyuki

2009-07-01

The possibility of radiation accident is very rare, but cannot be regarded as zero. Medical treatments are quite essential for a heavily exposed person in an occurrence of a radiation accident. Radiation dose distribution in a human body is useful information to carry out effectively the medical treatments. A radiation transport calculation utilizing the Monte Carlo method has an advantageous in the analysis of radiation dose inside of the body, which cannot be measured. An input file, which describes models for the accident condition and quantities of interest, should be prepared to execute the radiation transport calculation. Since the accident situation, however, cannot be prospected, many complicated procedures are needed to make effectively the input file soon after the occurrence of the accident. In addition, the calculated doses are to be given in output files, which usually include much information concerning the radiation transport calculation. Thus, Radiation Dose Assessment system for Radiation Accident (RADARAC) was developed to derive effectively radiation dose by using the MCNPX or MCNP code. RADARAC mainly consists of two parts. One part is RADARAC - INPUT, which involves three programs. A user can interactively set up necessary resources to make input files for the codes, with graphical user interfaces in a personnel computer. The input file includes information concerning the geometric structure of the radiation source and the exposed person, emission of radiations during the accident, physical quantities of interest and so on. The other part is RADARAC - DOSE, which has one program. The results of radiation doses can be effectively indicated with numerical tables, graphs and color figures visibly depicting dose distribution by using this program. These results are obtained from the outputs of the radiation transport calculations. It is confirmed that the system can effectively make input files with a few thousand lines and indicate more than 20

Radiation transport simulation of the Martian GCR surface flux and dose estimation using spherical geometry in PHITS compared to MSL-RAD measurements.

Science.gov (United States)

Flores-McLaughlin, John

2017-08-01

Planetary bodies and spacecraft are predominantly exposed to isotropic radiation environments that are subject to transport and interaction in various material compositions and geometries. Specifically, the Martian surface radiation environment is composed of galactic cosmic radiation, secondary particles produced by their interaction with the Martian atmosphere, albedo particles from the Martian regolith and occasional solar particle events. Despite this complex physical environment with potentially significant locational and geometric dependencies, computational resources often limit radiation environment calculations to a one-dimensional or slab geometry specification. To better account for Martian geometry, spherical volumes with respective Martian material densities are adopted in this model. This physical description is modeled with the PHITS radiation transport code and compared to a portion of measurements from the Radiation Assessment Detector of the Mars Science Laboratory. Particle spectra measured between 15 November 2015 and 15 January 2016 and PHITS model results calculated for this time period are compared. Results indicate good agreement between simulated dose rates, proton, neutron and gamma spectra. This work was originally presented at the 1st Mars Space Radiation Modeling Workshop held in 2016 in Boulder, CO. Copyright © 2017. Published by Elsevier Ltd.

Second order time evolution of the multigroup diffusion and P1 equations for radiation transport

International Nuclear Information System (INIS)

Olson, Gordon L.

2011-01-01

Highlights: → An existing multigroup transport algorithm is extended to be second-order in time. → A new algorithm is presented that does not require a grey acceleration solution. → The two algorithms are tested with 2D, multi-material problems. → The two algorithms have comparable computational requirements. - Abstract: An existing solution method for solving the multigroup radiation equations, linear multifrequency-grey acceleration, is here extended to be second order in time. This method works for simple diffusion and for flux-limited diffusion, with or without material conduction. A new method is developed that does not require the solution of an averaged grey transport equation. It is effective solving both the diffusion and P 1 forms of the transport equation. Two dimensional, multi-material test problems are used to compare the solution methods.

A hybrid transport-diffusion Monte Carlo method for frequency-dependent radiative-transfer simulations

International Nuclear Information System (INIS)

Densmore, Jeffery D.; Thompson, Kelly G.; Urbatsch, Todd J.

2012-01-01

Discrete Diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Implicit Monte Carlo radiative-transfer simulations in optically thick media. In DDMC, particles take discrete steps between spatial cells according to a discretized diffusion equation. Each discrete step replaces many smaller Monte Carlo steps, thus improving the efficiency of the simulation. In this paper, we present an extension of DDMC for frequency-dependent radiative transfer. We base our new DDMC method on a frequency-integrated diffusion equation for frequencies below a specified threshold, as optical thickness is typically a decreasing function of frequency. Above this threshold we employ standard Monte Carlo, which results in a hybrid transport-diffusion scheme. With a set of frequency-dependent test problems, we confirm the accuracy and increased efficiency of our new DDMC method.

Analyses of susceptibility to radiation-induced tumors: Prkdc, a candidate modifier of lymphomas

International Nuclear Information System (INIS)

Mori, Nobuko; Okumoto, Masaaki; Nakao, Ren

2003-01-01

BALB/cHeA (BALB/c) mice are susceptible to radiation-induced lymphomas, while STS/A (STS) mice are resistant. To analyze the difference in susceptibility between these two strains of mice, we have performed 3 independent studies: 1) mapping of apoptosis susceptibility gene Rapopl (chromosome 16) and identification of Prkdc as a candidate modifier of apoptosis as well as lymphomas, 2) analysis of congenic lines for Lyr, a gene responsible for the lymphoma resistance of STS mice on chromosome 4, 3) genetic analyses of lymphoma susceptibility using a backcross [(BALB/c x STS)F 1 x STS]. Analysis of Rapopl congenic lines indicated a minor contribution of the STS allele at the Rapopl (Prkdc) locus to the lymphoma resistance of STS mice. On the other hand, homozygous STS alleles at Lyr had a substantial, but less potent, effect on radiation lymphomagenesis. Furthermore, there was no single marker where the potent resistance of the STS mice was achieved with the homozygous STS alleles. These results suggest potential involvement of another loci in the resistance of STS mice. (author)

Radiation doses from radiation sources of neutrons and photons by different computer calculation

International Nuclear Information System (INIS)

Siciliano, F.; Lippolis, G.; Bruno, S.G.

1995-12-01

In the present paper the calculation technique aspects of dose rate from neutron and photon radiation sources are covered with reference both to the basic theoretical modeling of the MERCURE-4, XSDRNPM-S and MCNP-3A codes and from practical point of view performing safety analyses of irradiation risk of two transportation casks. The input data set of these calculations -regarding the CEN 10/200 HLW container and dry PWR spent fuel assemblies shipping cask- is frequently commented as for as connecting points of input data and understanding theoric background are concerned

Study on transport safety of refresh MOX fuel. Radiation dose from package hypothetically submerged into sea

International Nuclear Information System (INIS)

Tsumune, Daisuke; Suzuki; Hiroshi; Saegusa, Toshiari; Maruyama, Koki; Ito, Chihiro; Watabe, Naoto

1999-01-01

The sea transport of fresh MOX fuel from Europe to Japan is under planning. For the structure and equipment of transport ships for fresh MOX fuels, there is a special safety standard called the INF Code of IMO (International Maritime Organization). For transport of radioactive materials, there is a safety standard stipulated in Regulations for the Safe Transport of Radioactive Material issued by IAEA (International Atomic Energy Agency). Under those code and standard, fresh MOX fuel will be transported safely on the sea. However, a dose assessment has been made by assuming that a fresh MOX fuel package might be sunk into the sea by unexpected reasons. In the both cases for a package sunk at the coastal region and for that sunk at the ocean, the evaluated result of the dose equivalent by radiation exposure to the public are far below the dose equivalent limit of the ICRP recommendation (1 mSv/year). (author)

Atoms, Radiation, and Radiation Protection

CERN Document Server

Turner, James E

2007-01-01

Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

Reactor Dosimetry Applications Using RAPTOR-M3G:. a New Parallel 3-D Radiation Transport Code

Science.gov (United States)

Longoni, Gianluca; Anderson, Stanwood L.

2009-08-01

The numerical solution of the Linearized Boltzmann Equation (LBE) via the Discrete Ordinates method (SN) requires extensive computational resources for large 3-D neutron and gamma transport applications due to the concurrent discretization of the angular, spatial, and energy domains. This paper will discuss the development RAPTOR-M3G (RApid Parallel Transport Of Radiation - Multiple 3D Geometries), a new 3-D parallel radiation transport code, and its application to the calculation of ex-vessel neutron dosimetry responses in the cavity of a commercial 2-loop Pressurized Water Reactor (PWR). RAPTOR-M3G is based domain decomposition algorithms, where the spatial and angular domains are allocated and processed on multi-processor computer architectures. As compared to traditional single-processor applications, this approach reduces the computational load as well as the memory requirement per processor, yielding an efficient solution methodology for large 3-D problems. Measured neutron dosimetry responses in the reactor cavity air gap will be compared to the RAPTOR-M3G predictions. This paper is organized as follows: Section 1 discusses the RAPTOR-M3G methodology; Section 2 describes the 2-loop PWR model and the numerical results obtained. Section 3 addresses the parallel performance of the code, and Section 4 concludes this paper with final remarks and future work.

Hydrogenic Species Transport Assessments in Ceramic Aluminas Used in ITER ICRH H and CD and Diagnostic Systems

Energy Technology Data Exchange (ETDEWEB)

Moreno, C.; Sedano, L. A.

2007-09-27

Ceramic insulators will be used in the ITER Heating and Current Drive and Diagnostics (H and CD/D) systems as opto-electronic vacuum windows or as feed-troughs. Their performance as materials could come modified by the intake of deuterium-tritium which amounts might be enhanced by ionising radiation effects. Such vacuum windows have a primary safety role as tritium confinement barriers. Tritium transport analyses have major implications on the design and safety assessments of ITER RF H and CD systems. As it is shown, refined tritium transport release-rate models together with detailed parametric studies can precise such assessments. In addition such modeling serves as conceptual framework to quantify precise impact of underlying phenomena (ex. radiation-enhanced diffusion or potential effects of radiation damage on tritium transport through the Vacuum Window) and its fi nal impact on main transport parameters of interest for VW design: permeation flux and D/T inventories. In the present work it has been shown how, for electric implantation of ionized D,T in the VW being the major source for isotopes intake, an hybrid recombination/radiation enhanced diffusion regime determine H-isotopes transport kinetics in the window. Precise values for permeation fluxes and inventories are provided from solution of mass transport equations. Near and medium term work planning is advanced. (Author) 16 refs.

Hydrogenic Species Transport Assessments in Ceramic Aluminas Used in ITER ICRH H and CD and Diagnostic Systems

International Nuclear Information System (INIS)

Moreno, C.; Sedano, L. A.

2007-01-01

Ceramic insulators will be used in the ITER Heating and Current Drive and Diagnostics (H and CD/D) systems as opto-electronic vacuum windows or as feed-troughs. Their performance as materials could come modified by the intake of deuterium-tritium which amounts might be enhanced by ionising radiation effects. Such vacuum windows have a primary safety role as tritium confinement barriers. Tritium transport analyses have major implications on the design and safety assessments of ITER RF H and CD systems. As it is shown, refined tritium transport release-rate models together with detailed parametric studies can precise such assessments. In addition such modeling serves as conceptual framework to quantify precise impact of underlying phenomena (ex. radiation-enhanced diffusion or potential effects of radiation damage on tritium transport through the Vacuum Window) and its fi nal impact on main transport parameters of interest for VW design: permeation flux and D/T inventories. In the present work it has been shown how, for electric implantation of ionized D,T in the VW being the major source for isotopes intake, an hybrid recombination/radiation enhanced diffusion regime determine H-isotopes transport kinetics in the window. Precise values for permeation fluxes and inventories are provided from solution of mass transport equations. Near and medium term work planning is advanced. (Author) 16 refs

Line photon transport in a non-homogeneous plasma using radiative coupling coefficients

International Nuclear Information System (INIS)

Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Minguez, E.

2006-01-01

We present a steady-state collisional-radiative model for the calculation of level populations in non-homogeneous plasmas with planar geometry. The line photon transport is taken into account following an angle- and frequency-averaged escape probability model. Several models where the same approach has been used can be found in the literature, but the main difference between our model and those ones is that the details of geometry are exactly treated in the definition of coupling coefficients and a local profile is taken into account in each plasma cell. (authors)

Database supported electronic retrospective analyses in radiation oncology. Establishing a workflow using the example of pancreatic cancer

International Nuclear Information System (INIS)

Kessel, K.A.; Habermehl, D.; Bougatf, N.; Debus, J.; Combs, S.E.; Jaeger, A.; Floca, R.O.; Zhang, L.; Bendl, R.

2012-01-01

Purpose: Especially in the field of radiation oncology, handling a large variety of voluminous datasets from various information systems in different documentation styles efficiently is crucial for patient care and research. To date, conducting retrospective clinical analyses is rather difficult and time consuming. With the example of patients with pancreatic cancer treated with radio-chemotherapy, we performed a therapy evaluation by using an analysis system connected with a documentation system. Materials and methods: A total number of 783 patients have been documented into a professional, database-based documentation system. Information about radiation therapy, diagnostic images and dose distributions have been imported into the web-based system. Results: For 36 patients with disease progression after neoadjuvant chemoradiation, we designed and established an analysis workflow. After an automatic registration of the radiation plans with the follow-up images, the recurrence volumes are segmented manually. Based on these volumes the DVH (dose volume histogram) statistic is calculated, followed by the determination of the dose applied to the region of recurrence. All results are saved in the database and included in statistical calculations. Conclusion: The main goal of using an automatic analysis tool is to reduce time and effort conducting clinical analyses, especially with large patient groups. We showed a first approach and use of some existing tools, however manual interaction is still necessary. Further steps need to be taken to enhance automation. Already, it has become apparent that the benefits of digital data management and analysis lie in the central storage of data and reusability of the results. Therefore, we intend to adapt the analysis system to other types of tumors in radiation oncology. (orig.)

Uncertainty analyses of infiltration and subsurface flow and transport for SDMP sites

International Nuclear Information System (INIS)

Meyer, P.D.; Rockhold, M.L.; Gee, G.W.

1997-09-01

US Nuclear Regulatory Commission staff have identified a number of sites requiring special attention in the decommissioning process because of elevated levels of radioactive contaminants. Traits common to many of these sites include limited data characterizing the subsurface, the presence of long-lived radionuclides necessitating a long-term analysis (1,000 years or more), and potential exposure through multiple pathways. As a consequence of these traits, the uncertainty in predicted exposures can be significant. In addition, simplifications to the physical system and the transport mechanisms are often necessary to reduce the computational requirements of the analysis. Several multiple-pathway transport codes exist for estimating dose, two of which were used in this study. These two codes have built-in Monte Carlo simulation capabilities that were used for the uncertainty analysis. Several tools for improving uncertainty analyses of exposure estimates through the groundwater pathway have been developed and are discussed in this report. Generic probability distributions for unsaturated and saturated zone soil hydraulic parameters are presented. A method is presented to combine the generic distributions with site-specific water retention data using a Bayesian analysis. The resulting updated soil hydraulic parameter distributions can be used to obtain an updated estimate of the probability distribution of dose. The method is illustrated using a hypothetical decommissioning site

Mixed-hybrid finite element method for the transport equation and diffusion approximation of transport problems

International Nuclear Information System (INIS)

Cartier, J.

2006-04-01

This thesis focuses on mathematical analysis, numerical resolution and modelling of the transport equations. First of all, we deal with numerical approximation of the solution of the transport equations by using a mixed-hybrid scheme. We derive and study a mixed formulation of the transport equation, then we analyse the related variational problem and present the discretization and the main properties of the scheme. We particularly pay attention to the behavior of the scheme and we show its efficiency in the diffusion limit (when the mean free path is small in comparison with the characteristic length of the physical domain). We present academical benchmarks in order to compare our scheme with other methods in many physical configurations and validate our method on analytical test cases. Unstructured and very distorted meshes are used to validate our scheme. The second part of this thesis deals with two transport problems. The first one is devoted to the study of diffusion due to boundary conditions in a transport problem between two plane plates. The second one consists in modelling and simulating radiative transfer phenomenon in case of the industrial context of inertial confinement fusion. (author)

Department of Environmental and Radiation Transport Physics - Overview

International Nuclear Information System (INIS)

Woznicka, U.

2002-01-01

geological structures, in collaboration with the Institute of Geological Sciences of Polish Academy of Sciences. The geological fault system which surrounds the ''Las Wolski'' horst is covered with loess overburden. An evident increase in radon concentration in the upper loess layer is observed over the fault position. This may have important environmental implications. Several samples of soil taken from those areas were analysed for the concentration of natural isotopes (U, Th, and K). Natural radioactivity measurements in various samples (soils, rocks, raw, and building materials, etc.) have been carried out using low background spectrometers (with NaI(Tl) and HPGe detectors). We took part in the national inter-comparison concerning the methodology of ''radon-in-water'' measurements. The results are to be published. A joint project ''The Radon Centre - Non- Governmental International Scientific Network'' has been started in co-operation with the Central Mining Institute in Katowice. The main goals are to prepare and execute joint research projects and programmes, and to disseminate and put into practice the results of research activities of particular Network members. Neutron methods are an important part of nuclear geophysics and are also used in medical modalities. Investigations of the neutron transport parameters require usually the detection and/or calculation of spatial, time, and energy distributions of fast, epithermal and thermal neutrons, and of the accompanying γ radiation. The research has been directed into several aspects: - Basic theoretical and experimental investigation for the thermal neutron transport: a) the temperature behaviour of the pulsed parameters in a hydrogenous moderator, b) diffusion cooling in small two-region systems containing substances of different types of energy characteristics of thermal neutron scattering. - Calculations of the radiation field and energy deposition in the water beam dump for the TESLA electron-positron collider for

Study of radiative ablation to low-Z material and energy transport

International Nuclear Information System (INIS)

Yang Jiamin; Ding Yaonan; Miao Wenyong; Sun Kexu; Yi Rongqing; Chen Zhenglin; Wang Hongbin; Li Sanwei; Wang Yaomei; Wen Shuhuai; Zheng Zhijian; Zhang Wenhai; Yu Yanning

1998-12-01

X-ray emissions from the gold foil target, irradiated by 0.35 μm laser on the Xingguang facility, have been studied. A clean and intense X-ray source has been obtained from the rear of gold foil target by selection of irradiating laser parameters. Then, characteristics of radiation ablation to low-Z materials C 8 H 8 and C 10 H 16 O 5 and energy transport have been investigated comprehensively. Experimental results show that mass ablative rate of C 10 H 16 O 5 are greater than those of C 8 H 8 due to its better match with the ablative source spectra

Data structures and language elements for automated transport calculations for neutron and gamma radiation

International Nuclear Information System (INIS)

Rexer, G.

1978-12-01

Computer-aided design of nuclear shielding and irradiation facilities is characterized by studies of different design variants in order to determine which facilities are safe and still economicol. The design engineer has a very complex task including the formulation of calculation models, data linking of programs and data, and the management of large data stores. Integrated modular program systems with centralized module and data management make it possible to treat these problems in a more simplified and automatic manner. The paper describes a system of this type for the field of radiation transport and radiation shielding. The basis is the modular system RSYST II which has a dynamic hierarchical scheme for the structuring of problem data in a central data base. (orig./RW) [de

The shielding against radiation produced by powder metallurgy with tungsten copper alloy applied on transport equipment for radio-pharmaceutical products

International Nuclear Information System (INIS)

Cione, Francisco C.; Sene, Frank F.; Souza, Armando C. de; Betini, Evandro G.; Rossi, Jesualdo L.; Rizzuto, Marcia A.

2015-01-01

Safety is mandatory on medicine radiopharmaceutical transportation and dependent on radiation shielding material. The focus of the present work is to minimize the use of harmful materials as lead and depleted uranium usually used in packages transportation. The tungsten-copper composite obtained by powder metallurgy (PM) is non-toxic. In powder metallurgy the density and the porosity of the compacted parts depends basically upon particle size distribution of each component, mixture, compacting pressure and sintering temperature cycle. The tungsten-copper composite, when used for shielding charged particles, X-rays, gamma photons or other photons of lower energy require proper interpretation of the radiation transport phenomena. The radioactive energy reduction varies according to the porosity and density of the materials used as shielding. The main factor for radiation attenuation is the cross section value for tungsten. The motivation research factor is an optimization of the tungsten and cooper composition in order to achieve the best linear absorption coefficient given by equation I (x) = I 0 e (-ux) . Experiments were conducted to quantify the effective radiation shielding properties of tungsten-copper composite produced by PM, varying the cooper amount in the composite. The studied compositions were 15%, 20% and 25% copper in mass. The Compaction pressure was 270 MPa and the sintering atmosphere was in 1.1 atm in N 2 +H 2 . The sintering temperature was 980 deg C for 2 h. The linear absorption coefficient factor was similar either for the green and the sintered compacts, due the amount of porosity did not affect the radiation attenuation. Thus the sintered was meant for size reduction and mechanical properties enhancement. (author)

The shielding against radiation produced by powder metallurgy with tungsten copper alloy applied on transport equipment for radio-pharmaceutical products

Energy Technology Data Exchange (ETDEWEB)

Cione, Francisco C.; Sene, Frank F.; Souza, Armando C. de; Betini, Evandro G.; Rossi, Jesualdo L., E-mail: fceoni@hotmail.com, E-mail: ffsene@hotmail.com, E-mail: armandocirilo@yahoo.com, E-mail: evandrobetini@gmail.com, E-mail: jelrossi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rizzuto, Marcia A., E-mail: marizzutto@if.usp.br [Universidade de Sao Paulo (IF/USP), SP (Brazil). Instituto de Fisica

2015-07-01

Safety is mandatory on medicine radiopharmaceutical transportation and dependent on radiation shielding material. The focus of the present work is to minimize the use of harmful materials as lead and depleted uranium usually used in packages transportation. The tungsten-copper composite obtained by powder metallurgy (PM) is non-toxic. In powder metallurgy the density and the porosity of the compacted parts depends basically upon particle size distribution of each component, mixture, compacting pressure and sintering temperature cycle. The tungsten-copper composite, when used for shielding charged particles, X-rays, gamma photons or other photons of lower energy require proper interpretation of the radiation transport phenomena. The radioactive energy reduction varies according to the porosity and density of the materials used as shielding. The main factor for radiation attenuation is the cross section value for tungsten. The motivation research factor is an optimization of the tungsten and cooper composition in order to achieve the best linear absorption coefficient given by equation I{sub (x)} = I{sub 0}e{sup (-ux)}. Experiments were conducted to quantify the effective radiation shielding properties of tungsten-copper composite produced by PM, varying the cooper amount in the composite. The studied compositions were 15%, 20% and 25% copper in mass. The Compaction pressure was 270 MPa and the sintering atmosphere was in 1.1 atm in N{sub 2}+H{sub 2}. The sintering temperature was 980 deg C for 2 h. The linear absorption coefficient factor was similar either for the green and the sintered compacts, due the amount of porosity did not affect the radiation attenuation. Thus the sintered was meant for size reduction and mechanical properties enhancement. (author)

Validation of the transportation computer codes HIGHWAY, INTERLINE, RADTRAN 4, and RISKIND

International Nuclear Information System (INIS)

Maheras, S.J.; Pippen, H.K.

1995-05-01

The computer codes HIGHWAY, INTERLINE, RADTRAN 4, and RISKIND were used to estimate radiation doses from the transportation of radioactive material in the Department of Energy Programmatic Spent Nuclear Fuel Management and Idaho National Engineering Laboratory Environmental Restoration and Waste Management Programs Environmental Impact Statement. HIGHWAY and INTERLINE were used to estimate transportation routes for truck and rail shipments, respectively. RADTRAN 4 was used to estimate collective doses from incident-free transportation and the risk (probability x consequence) from transportation accidents. RISKIND was used to estimate incident-free radiation doses for maximally exposed individuals and the consequences from reasonably foreseeable transportation accidents. The purpose of this analysis is to validate the estimates made by these computer codes; critiques of the conceptual models used in RADTRAN 4 are also discussed. Validation is defined as ''the test and evaluation of the completed software to ensure compliance with software requirements.'' In this analysis, validation means that the differences between the estimates generated by these codes and independent observations are small (i.e., within the acceptance criterion established for the validation analysis). In some cases, the independent observations used in the validation were measurements; in other cases, the independent observations used in the validation analysis were generated using hand calculations. The results of the validation analyses performed for HIGHWAY, INTERLINE, RADTRAN 4, and RISKIND show that the differences between the estimates generated using the computer codes and independent observations were small. Based on the acceptance criterion established for the validation analyses, the codes yielded acceptable results; in all cases the estimates met the requirements for successful validation

Modeling of radiation heat transport in complex ladder-like structures placed in rectangular enclosures

International Nuclear Information System (INIS)

Unal, C.; Bohl, W.R.; Pasamehmetoglu, K.O.

1999-01-01

Complex ladder-like structures recently have been considered as the target design for accelerator applications. The decay heat, during a postulated beyond design-basis loss-of-coolant accident in the target where all normal and emergency cooling fails, is removed mainly by radiation heat transfer. Modeling of the radiation transport in complex ladder-like structures has several challenges and limitations when the standard net-radiation model is used. This paper proposes a simplified lumped, or 'hot-rung' model, that considers the worst elements and utilizes the standard net-radiation method. The net-radiation model would under-predict structure temperatures if surfaces were subject to non-uniform radiosity. The proposed model was assessed to suggest corrections to account for the non-uniform radiosity. The non-uniform radiosity effect causes the proposed hot-rung model to under-predict the center-rung temperatures by ∼4-74 C when all parametrics, including temperatures up to 1500 C, were considered. These temperatures are small. The proposed model predicted that an important effect of decreasing the emissivity was smoothing of non-isothermal effects. The radiosity effects are more pronounced when there are strong temperature gradients. Uniform rung temperatures tend to decrease the radiosity effects. We concluded that a relatively simple model that is conservative with respect to radiosity effects could be developed. (orig.)

Safe handling of radiation sources

International Nuclear Information System (INIS)

Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

2004-01-01

This chapter discussed the subjects related to the safe handling of radiation sources: type of radiation sources, method of use: transport within premises, transport outside premises; Disposal of Gamma Sources

The Coupling of Radiation and Hydrodynamics

International Nuclear Information System (INIS)

Lowrie, R.B.; Morel, J.E.; Hittinger, J.A.

1999-01-01

The coupling of radiation transport and hydrodynamics is discussed for the Eulerian frame. The discussion is aimed at developing a suitable set of equations for nonrelativistic radiation hydrodynamics (RHD) that can be numerically integrated using high-resolution methods for conservation laws. We outline how numerical methods based on a wave decomposition may be developed, along with the importance of conservation, particularly in the equilibrium regime. The properties of the RHD equations are examined through asymptotic and dispersion analyses. The conditions required to obtain the classical equilibrium limit are rigorously studied. The results show that a simple coupling term developed recently by Morel, which retains a minimum of relativistic corrections, may be sufficient for nonrelativistic flows. We also give two constraints on the relativistic corrections that result in retaining terms on the order of the truncation. In addition, the dispersion results for the P 1 approximation are studied in detail and are compared with both the exact-transport results and a full relativistic treatment. We also examine some nonintuitive behavior in the dispersion results. copyright copyright 1999. The American Astronomical Society

Charge transport properties of CdMnTe radiation detectors

Directory of Open Access Journals (Sweden)

Prokopovich D. A.

2012-10-01

Full Text Available Growth, fabrication and characterization of indium-doped cadmium manganese telluride (CdMnTe radiation detectors have been described. Alpha-particle spectroscopy measurements and time resolved current transient measurements have yielded an average charge collection efficiency approaching 100 %. Spatially resolved charge collection efficiency maps have been produced for a range of detector bias voltages. Inhomogeneities in the charge transport of the CdMnTe crystals have been associated with chains of tellurium inclusions within the detector bulk. Further, it has been shown that the role of tellurium inclusions in degrading charge collection is reduced with increasing values of bias voltage. The electron drift velocity was calculated from the rise time distribution of the preamplifier output pulses at each measured bias. From the dependence of drift velocity on applied electric field the electron mobility was found to be μn = (718 ± 55 cm2/Vs at room temperature.

Low Z impurity transport in tokamaks. [Neoclassical transport theory

Energy Technology Data Exchange (ETDEWEB)

Hawryluk, R.J.; Suckewer, S.; Hirshman, S.P.

1978-10-01

Low Z impurity transport in tokamaks was simulated with a one-dimensional impurity transport model including both neoclassical and anomalous transport. The neoclassical fluxes are due to collisions between the background plasma and impurity ions as well as collisions between the various ionization states. The evaluation of the neoclassical fluxes takes into account the different collisionality regimes of the background plasma and the impurity ions. A limiter scrapeoff model is used to define the boundary conditions for the impurity ions in the plasma periphery. In order to account for the spectroscopic measurements of power radiated by the lower ionization states, fluxes due to anomalous transport are included. The sensitivity of the results to uncertainties in rate coefficients and plasma parameters in the periphery are investigated. The implications of the transport model for spectroscopic evaluation of impurity concentrations, impurity fluxes, and radiated power from line emission measurements are discussed.

Germany: Exposure of Transport Workers During the Transport of Most Frequently Transported NORM in Germany

International Nuclear Information System (INIS)

2013-01-01

The German national report to this CRP was focused on the following services according to the research agreement: (1) Status review, analysis and evaluation of the radiation exposure imposed by shipment and expected exposure of the shipment staff of the most relevant NORM in Germany; (2) Development of evaluation criteria and safety requirements to provide adequate safety standards for the transportation of NORM; (3) Development and application of procedures to determine the limits for exempt materials/consignments for transportation according to German Transport Regulations for all NORM. For the analysis and evaluation of the radiation exposure imposed by shipment of NORM for the following materials, a couple of transport scenarios were defined and the dose to transport workers was calculated. - Tantalum raw materials; - Raw phosphate; - Pipe scales and sludge from oil and gas exploitation; - Coal ash; - Waste rock material from uranium mining; - Zircon raw materials; - Titanium dioxide raw materials; - Filter gravel from waterworks

The changing nature of nuclear transport

International Nuclear Information System (INIS)

Brobst, W.A.

1976-01-01

The IAEA's efforts in transport safety have been proven through 25 years of nearly accident-free transport, with no evidence of death or injury from the nuclear characteristics of those shipments. Much testing has been done over the last five years to verify the technical bases for the IAEA Regulations. Rather than being complacent with the past, we should instead see ourselves at a turning point for the solution of problems coming up in the next few years. The number of shipments will increase drastically and this will result in changes of risk levels. A number of critical problems will be discussed: (1) lack of public acceptance of nuclear shipment safety; (2) transport safeguards; (3) incompleteness in the IAEA package damage tests; (4) need for innovative technology for spent fuel casks; (5) reduction of radiation dose to the public; (6) quality assurance; (7) engineering analyses versus scale-model and full-scale testing; and (8) transport controls. A recommendation is made to the IAEA to set up immediately a study group to define these problems, list alternatives and options, and recommend corrective actions. (author)

Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field

Energy Technology Data Exchange (ETDEWEB)

Wang, C., E-mail: cwang@mail.sim.ac.cn; Wang, F.; Cao, J. C., E-mail: jccao@mail.sim.ac.cn [Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050 (China)

2014-09-01

Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation.

Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field

International Nuclear Information System (INIS)

Wang, C.; Wang, F.; Cao, J. C.

2014-01-01

Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation

Terahertz radiation induced chaotic electron transport in semiconductor superlattices with a tilted magnetic field.

Science.gov (United States)

Wang, C; Wang, F; Cao, J C

2014-09-01

Chaotic electron transport in semiconductor superlattice induced by terahertz electric field that is superimposed on a dc electric field along the superlattice axis are studied using the semiclassical motion equations including the effect of dissipation. A magnetic field that is tilted relative to the superlattice axis is also applied to the system. Numerical simulation shows that electrons in superlattice miniband exhibit complicate nonlinear oscillating modes with the influence of terahertz radiation. Transitions between frequency-locking and chaos via pattern forming bifurcations are observed with the varying of terahertz amplitude. It is found that the chaotic regions gradually contract as the dissipation increases. We attribute the appearance of complicate nonlinear oscillation in superlattice to the interaction between terahertz radiation and internal cooperative oscillating mode relative to Bloch oscillation and cyclotron oscillation.

Mixed-hybrid finite element method for the transport equation and diffusion approximation of transport problems; Resolution de l'equation du transport par une methode d'elements finis mixtes-hybrides et approximation par la diffusion de problemes de transport

Energy Technology Data Exchange (ETDEWEB)

Cartier, J

2006-04-15

This thesis focuses on mathematical analysis, numerical resolution and modelling of the transport equations. First of all, we deal with numerical approximation of the solution of the transport equations by using a mixed-hybrid scheme. We derive and study a mixed formulation of the transport equation, then we analyse the related variational problem and present the discretization and the main properties of the scheme. We particularly pay attention to the behavior of the scheme and we show its efficiency in the diffusion limit (when the mean free path is small in comparison with the characteristic length of the physical domain). We present academical benchmarks in order to compare our scheme with other methods in many physical configurations and validate our method on analytical test cases. Unstructured and very distorted meshes are used to validate our scheme. The second part of this thesis deals with two transport problems. The first one is devoted to the study of diffusion due to boundary conditions in a transport problem between two plane plates. The second one consists in modelling and simulating radiative transfer phenomenon in case of the industrial context of inertial confinement fusion. (author)

Experimental studies and modelling of high radiation and high density plasmas in the ASDEX upgrade tokamak

Energy Technology Data Exchange (ETDEWEB)

Casali, Livia

2015-11-24

Fusion plasmas contain impurities, either intrinsic originating from the wall, or injected willfully with the aim of reducing power loads on machine components by converting heat flux into radiation. The understanding and the prediction of the effects of these impurities and their radiation on plasma performances is crucial in order to retain good confinement. In addition, it is important to understand the impact of pellet injection on plasma performance since this technique allows higher core densities which are required to maximise the fusion power. This thesis contributes to these efforts through both experimental investigations and modelling. Experiments were conducted at ASDEX Upgrade which has a full-W wall. Impurity seeding was applied to H-modes by injecting nitrogen and also medium-Z impurities such as Kr and Ar to assess the impact of both edge and central radiation on confinement. A database of about 25 discharges has been collected and analysed. A wide range of plasma parameters was achieved up to ITER relevant values such as high Greenwald and high radiation fractions. Transport analyses taking into account the radiation distribution reveal that edge localised radiation losses do not significantly impact confinement as long as the H-mode pedestal is sustained. N seeding induces higher pedestal pressure which is propagated to the core via profile stiffness. Central radiation must be limited and controlled to avoid confinement degradation. This requires reliable control of the impurity concentration but also possibilities to act on the ELM frequency which must be kept high enough to avoid an irreversible impurity accumulation in the centre and the consequent radiation collapse. The key role of the f{sub ELM} is confirmed also by the analysis of N+He discharges. Non-coronal effects affect the radiation of low-Z impurities at the plasma edge. Due to the radial transport, the steep temperature gradients and the ELM flush out, a local equilibrium cannot be

Development and Implementation of Photonuclear Cross-Section Data for Mutually Coupled Neutron-Photon Transport Calculations in the Monte Carlo N-Particle (MCNP) Radiation Transport Code

International Nuclear Information System (INIS)

White, Morgan C.

2000-01-01

The fundamental motivation for the research presented in this dissertation was the need to development a more accurate prediction method for characterization of mixed radiation fields around medical electron accelerators (MEAs). Specifically, a model is developed for simulation of neutron and other particle production from photonuclear reactions and incorporated in the Monte Carlo N-Particle (MCNP) radiation transport code. This extension of the capability within the MCNP code provides for the more accurate assessment of the mixed radiation fields. The Nuclear Theory and Applications group of the Los Alamos National Laboratory has recently provided first-of-a-kind evaluated photonuclear data for a select group of isotopes. These data provide the reaction probabilities as functions of incident photon energy with angular and energy distribution information for all reaction products. The availability of these data is the cornerstone of the new methodology for state-of-the-art mutually coupled photon-neutron transport simulations. The dissertation includes details of the model development and implementation necessary to use the new photonuclear data within MCNP simulations. A new data format has been developed to include tabular photonuclear data. Data are processed from the Evaluated Nuclear Data Format (ENDF) to the new class ''u'' A Compact ENDF (ACE) format using a standalone processing code. MCNP modifications have been completed to enable Monte Carlo sampling of photonuclear reactions. Note that both neutron and gamma production are included in the present model. The new capability has been subjected to extensive verification and validation (V and V) testing. Verification testing has established the expected basic functionality. Two validation projects were undertaken. First, comparisons were made to benchmark data from literature. These calculations demonstrate the accuracy of the new data and transport routines to better than 25 percent. Second, the ability to

Development and Implementation of Photonuclear Cross-Section Data for Mutually Coupled Neutron-Photon Transport Calculations in the Monte Carlo N-Particle (MCNP) Radiation Transport Code

Energy Technology Data Exchange (ETDEWEB)

White, Morgan C. [Univ. of Florida, Gainesville, FL (United States)

2000-07-01

The fundamental motivation for the research presented in this dissertation was the need to development a more accurate prediction method for characterization of mixed radiation fields around medical electron accelerators (MEAs). Specifically, a model is developed for simulation of neutron and other particle production from photonuclear reactions and incorporated in the Monte Carlo N-Particle (MCNP) radiation transport code. This extension of the capability within the MCNP code provides for the more accurate assessment of the mixed radiation fields. The Nuclear Theory and Applications group of the Los Alamos National Laboratory has recently provided first-of-a-kind evaluated photonuclear data for a select group of isotopes. These data provide the reaction probabilities as functions of incident photon energy with angular and energy distribution information for all reaction products. The availability of these data is the cornerstone of the new methodology for state-of-the-art mutually coupled photon-neutron transport simulations. The dissertation includes details of the model development and implementation necessary to use the new photonuclear data within MCNP simulations. A new data format has been developed to include tabular photonuclear data. Data are processed from the Evaluated Nuclear Data Format (ENDF) to the new class ''u'' A Compact ENDF (ACE) format using a standalone processing code. MCNP modifications have been completed to enable Monte Carlo sampling of photonuclear reactions. Note that both neutron and gamma production are included in the present model. The new capability has been subjected to extensive verification and validation (V&V) testing. Verification testing has established the expected basic functionality. Two validation projects were undertaken. First, comparisons were made to benchmark data from literature. These calculations demonstrate the accuracy of the new data and transport routines to better than 25 percent. Second

Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines

International Nuclear Information System (INIS)

Leibhard, S.; Smida, J.

1996-01-01

Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique -the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.) [de

C5 Benchmark Problem with Discrete Ordinate Radiation Transport Code DENOVO

Energy Technology Data Exchange (ETDEWEB)

Yesilyurt, Gokhan [ORNL; Clarno, Kevin T [ORNL; Evans, Thomas M [ORNL; Davidson, Gregory G [ORNL; Fox, Patricia B [ORNL

2011-01-01

The C5 benchmark problem proposed by the Organisation for Economic Co-operation and Development/Nuclear Energy Agency was modeled to examine the capabilities of Denovo, a three-dimensional (3-D) parallel discrete ordinates (S{sub N}) radiation transport code, for problems with no spatial homogenization. Denovo uses state-of-the-art numerical methods to obtain accurate solutions to the Boltzmann transport equation. Problems were run in parallel on Jaguar, a high-performance supercomputer located at Oak Ridge National Laboratory. Both the two-dimensional (2-D) and 3-D configurations were analyzed, and the results were compared with the reference MCNP Monte Carlo calculations. For an additional comparison, SCALE/KENO-V.a Monte Carlo solutions were also included. In addition, a sensitivity analysis was performed for the optimal angular quadrature and mesh resolution for both the 2-D and 3-D infinite lattices of UO{sub 2} fuel pin cells. Denovo was verified with the C5 problem. The effective multiplication factors, pin powers, and assembly powers were found to be in good agreement with the reference MCNP and SCALE/KENO-V.a Monte Carlo calculations.

Radiation safety

International Nuclear Information System (INIS)

Woods, D.A.

1982-01-01

Sections include: dose units, dose limits, dose rate, potential hazards of ionizing radiations, control of internal and external radiation exposure, personal dosemeters, monitoring programs and transport of radioactive material (packaging and shielding)

A study on tokamak fusion reactor - Numerical analyses of MHD equilibrium= and edge plasma transport in tokamak fusion reactor with divertor configurations

Energy Technology Data Exchange (ETDEWEB)

Hong, Sang Hee; Lim, Ki Hang; Kang, Kyung Doo; Ryu, Ji Myung; Kim, Duk Kyu [Seoul National University, Seoul (Korea, Republic of); Cho, Soo Won [Kyungki Unviersity, Suwon (Korea, Republic of)

1995-08-01

In the present project for developing the numerical codes of 2-DMHD equilibrium, edge plasma transport and neutral particle transport for the tokamak plasmas, we compute the plasma equilibrium of double null type and calculate the external coil currents and the plasma parameters used for operation and control data. Also the numerical algorithm is developed to analyse the behavior of edge plasmas in poloidal and radial directions and the programming and debugging of a 2-D transport code are completed. Furthermore, a neutral particle transport code for the edge region is developed and then used for the analysis of the neutral transport phenomena giving the sources in the fluid equations, and expected to supply the input parameters for the edge plasma transport code. 34 refs., 5 tabs., 28 figs. (author)

Hyperspectral Analyses of Wild 2 Grains Using Synchrotron Radiation

Science.gov (United States)

Simionovici, A. S.; Lemelle, L.; Ferroir, T.; Gillet, P.; Borg, J.; Grossemy, F.; Djouadi, Z.; Bleuet, P.; Susini, J.

2006-12-01

This work is part of the Preliminary Examination Team (PET) on Bulk Chemistry investigation of Wild 2 cometary grains brought back to Earth by the NASA Stardust mission [1]. X-rays are among the least destructive yet sensitive micro-probes, capable of analysing minute samples embedded in low density collectors, so methods based on Synchrotron Radiation had access to Stardust samples in priority. The main goal of the PET was to produce a preliminary characterization of the abundance and nature of the elements present in the returned samples [2]. In this phase it was paramount to analyze the grains in-situ, in the aerogel foam of the collectors to record the total mass fragments and avoid extraction risks. We have performed measurements on beamlines ID22/ID21 of the ESRF synchrotron in Grenoble, France, devoted to high/low energy microspectroscopy and recorded results on a collection of 6 keystones. Terminal particles as well as fragmentation tracks in the aerogel were mapped out with micron resolution, recording total mass composition for elements of Z>15 by means of X-ray fluorescence [3], as well as structural information by X-ray diffraction. This allowed the direct identification of the mineralogy of some of the grains. Finally, we recorded the evolution of the charge states of S and Fe as a function of the position in the track by means of micro-Xanes measurements. All these analyses were combined to produce a description of the Wild 2 cometary grains [4], as well as a history of their formation and of the thermal interactions during their slowing down in the aerogel collectors. [1] Brownlee, D. E. et al., LPSC XXXVII, abstract nr. 2286, 2006. [2] G. J. Flynn et al., LPSC XXXVII, abstract nr. 1217, 2006. [3] A. Simionovici, P. Chevallier, Chap. 7, Handbook of Practical X-Ray Fluorescence Analysis, 66-83, Springer, 2006. [4] G. J. Flynn et al., Science, (submitted), 2006.

Radiation leakage in nuclear ship 'MUTSU'

International Nuclear Information System (INIS)

Ando, Yoshio; Miyasaka, Shun-ichi; Takeuchi, Kiyoshi.

1975-01-01

Associated with the radiation leakage in MUTSU occurred in September 1974, this report reviews the shielding design for MUTSU, radiation measurement and inspection activities by a survey group, and 2 dimensional analysis on the behavior of fast neutrons to shielding based on Ssub(N) codes. In the first part, the purpose and the structure of the primary and the secondary shields of MUTSU are briefly illustrated. In the second part, the progress of the series of affairs is explained, starting from zero power criticality experiment, through discovery of radiation leakage in output-increasing test, sending of a survey group for various measurement and inspection, and finally to the conclusion drawn by the survey group. In the third part, various numerical analyses performed to investigate into the leakage are illustrated with their results. The transport codes used were ANISN, TWOTRAN, SPAN, and PALLAS-2DCY. As a result of those inspection and calculation, it was found that the radiation leakage was due to fast neutrons coming through the gap between the reactor vessel and the primary shield. (Aoki, K.)

Evaluation of secondary exposure doses to transportation and medical personnel in the radiation emergency medicine

International Nuclear Information System (INIS)

Kato, Hideki; Suzuki, Shoichi; Koga, Sukehiko; Mukoyama, Takashi; Tomatsu, Hirotaka; Suzuki, Yusuke

2009-01-01

Radionuclide contamination is one of the accidents that might occur while carrying out a periodical inspection of nuclear power stations during normal reactor operation. When such an accident occurs, rescue and medical personnel, involved in transporting and treating affected workers run the risk of exposure to secondary radiation. In this study, the ambient dose equivalent rate at a certain distance from the surface of the human body contaminated with typical radioactive corrosion products was calculated. Further, the relationships among the adhesion area, contamination density, and secondary exposure dose were clarified. The secondary exposure dose and permissible working hours in a radiation emergency medicine were estimated by presenting these relationships in the form of a chart and by specifying the contamination levels. (author)

Analysis of radiation doses from operation of postulated commercial spent fuel transportation systems: Analysis of a system containing a monitored retrievable storage facility

International Nuclear Information System (INIS)

Smith, R.I.; Daling, P.M.; Faletti, D.W.

1992-04-01

This addendum report extends the original study of the estimated radiation doses to the public and to workers resulting from transporting spent nuclear fuel from commercial nuclear power reactor stations through the federal waste management system (FWMS), to a system that contains a monitored retrievable storage (MRS) facility. The system concepts and designs utilized herein are consistent with those used in the original study (circa 1985--1987). Because the FWMS design is still evolving, the results of these analyses may no longer apply to the design for casks and cask handling systems that are currently being considered. Four system scenarios are examined and compared with the reference No-MRS scenario (all spent fuel transported directly from the reactors to the western repository in standard-capacity truck and rail casks). In Scenarios 1 and 2, an MRS facility is located in eastern United States and ships either intact fuel assemblies or consolidated fuel rods and compacted assembly hardware in canisters. In Scenarios 3 and 4, an MRS facility is located in the western United States and ship either intact fuel assemblies or consolidated fuel rods and compacted assembly hardware in canisters

Accurate and efficient radiation transport in optically thick media -- by means of the Symbolic Implicit Monte Carlo method in the difference formulation

International Nuclear Information System (INIS)

Szoke, A; Brooks, E D; McKinley, M; Daffin, F

2005-01-01

The equations of radiation transport for thermal photons are notoriously difficult to solve in thick media without resorting to asymptotic approximations such as the diffusion limit. One source of this difficulty is that in thick, absorbing media thermal emission is almost completely balanced by strong absorption. In a previous publication [SB03], the photon transport equation was written in terms of the deviation of the specific intensity from the local equilibrium field. We called the new form of the equations the difference formulation. The difference formulation is rigorously equivalent to the original transport equation. It is particularly advantageous in thick media, where the radiation field approaches local equilibrium and the deviations from the Planck distribution are small. The difference formulation for photon transport also clarifies the diffusion limit. In this paper, the transport equation is solved by the Symbolic Implicit Monte Carlo (SIMC) method and a comparison is made between the standard formulation and the difference formulation. The SIMC method is easily adapted to the derivative source terms of the difference formulation, and a remarkable reduction in noise is obtained when the difference formulation is applied to problems involving thick media

Correlation and regression analyses of genetic effects for different types of cells in mammals under radiation and chemical treatment

International Nuclear Information System (INIS)

Slutskaya, N.G.; Mosseh, I.B.

2006-01-01

Data about genetic mutations under radiation and chemical treatment for different types of cells have been analyzed with correlation and regression analyses. Linear correlation between different genetic effects in sex cells and somatic cells have found. The results may be extrapolated on sex cells of human and mammals. (authors)

Calculation codes in radiation protection, radiation physics and dosimetry

International Nuclear Information System (INIS)

2003-01-01

These scientific days had for objective to draw up the situation of calculation codes of radiation transport, of sources estimation, of radiation doses managements and to draw the future perspectives. (N.C.)

Mixed-hybrid finite element method for the transport equation and diffusion approximation of transport problems; Resolution de l'equation du transport par une methode d'elements finis mixtes-hybrides et approximation par la diffusion de problemes de transport

Energy Technology Data Exchange (ETDEWEB)

Cartier, J

2006-04-15

This thesis focuses on mathematical analysis, numerical resolution and modelling of the transport equations. First of all, we deal with numerical approximation of the solution of the transport equations by using a mixed-hybrid scheme. We derive and study a mixed formulation of the transport equation, then we analyse the related variational problem and present the discretization and the main properties of the scheme. We particularly pay attention to the behavior of the scheme and we show its efficiency in the diffusion limit (when the mean free path is small in comparison with the characteristic length of the physical domain). We present academical benchmarks in order to compare our scheme with other methods in many physical configurations and validate our method on analytical test cases. Unstructured and very distorted meshes are used to validate our scheme. The second part of this thesis deals with two transport problems. The first one is devoted to the study of diffusion due to boundary conditions in a transport problem between two plane plates. The second one consists in modelling and simulating radiative transfer phenomenon in case of the industrial context of inertial confinement fusion. (author)

Testing and implementation of a transportable and robust radio-element mapping system

Directory of Open Access Journals (Sweden)

Jacques Bezuidenhout

2015-09-01

Full Text Available Gamma ray spectroscopy has been successfully applied as a survey tool in the fields of morphology, geology and mineral exploration. Gamma ray surveys are regularly done at ground level, which frequently requires transecting remote and unforgiving environments. Thus a need for the development of a transportable, robust and portable gamma ray detection system was identified. In addition to collecting radiation data, such a system was required to also provide the geographic position of the data and allow for various analyses tools to be utilised in the field. These functions were achieved by integrating a USB-driven scintillation detector with a field tablet and creating software to control acquisition and analyses of radiation data, as well as logging position. The system was tested in different geographical locations under different modes of transport. The instrument was tested by employing several different methods of data analysis in order to extract natural nuclide condensations. The consistency in the obtained data demonstrated the reliability of the instrument in the different environments. The system also successfully replicated previous radio-element survey findings and provided information on several geographical phenomena, including information on the geology, paved road structure and beach sediment characteristics.

Comparative analyses of forest fuels in a life cycle perspective with a focus on transport systems

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Lisa Naeslund [Ecotechnology, Department of Engineering, Physics and Mathematics, Mid Sweden University, SE-831 25 Oestersund (Sweden)

2008-08-15

Local, national and international transportation of forest fuels with regard to costs, primary energy use and CO{sub 2} emission was analysed. The main issue was the extent to which both mode and distance of transport affect the monetary cost, CO{sub 2} emission and primary energy use arising from the use of various types of forest residues for energy purpose. Local applications proved the most efficient options of those studied. Chipping of bundles at a terminal, for transport by rail and sea to national or international end-users, has low costs and produces only modest CO{sub 2} emissions. For the pellet options, the cost is about the same as for chipping, but require more primary energy and emit more CO{sub 2}. The traditional chipping system is more expensive than the other options. The costs of the international options over a transport distance of 1100 km vary between 21 and 28 EUR{sub 2007}/MWh, whereas pellet options cost between 22 and 25 EUR{sub 2007}/MWh. The primary energy required for transport of logging residues vis-a-vis pellets falls in the range 4-7% and 2-4%, respectively, of the bio-energy delivered. The primary energy needed to produce pellets gives them a lower fossil fuel substitution rate per hectare, compared with bundle systems. Similarly, for chip systems vis-a-vis bundle systems, the biomass delivered to the conversion plant is reduced by the greater physical dry-matter losses entailed by chipping systems in the forest-fuel chain. (author)

Development and application of neutron transport methods and uncertainty analyses for reactor core calculations. Technical report; Entwicklung und Einsatz von Neutronentransportmethoden und Unsicherheitsanalysen fuer Reaktorkernberechnungen. Technischer Bericht

Energy Technology Data Exchange (ETDEWEB)

Zwermann, W.; Aures, A.; Bernnat, W.; and others

2013-06-15

This report documents the status of the research and development goals reached within the reactor safety research project RS1503 ''Development and Application of Neutron Transport Methods and Uncertainty Analyses for Reactor Core Calculations'' as of the 1{sup st} quarter of 2013. The superordinate goal of the project is the development, validation, and application of neutron transport methods and uncertainty analyses for reactor core calculations. These calculation methods will mainly be applied to problems related to the core behaviour of light water reactors and innovative reactor concepts. The contributions of this project towards achieving this goal are the further development, validation, and application of deterministic and stochastic calculation programmes and of methods for uncertainty and sensitivity analyses, as well as the assessment of artificial neutral networks, for providing a complete nuclear calculation chain. This comprises processing nuclear basis data, creating multi-group data for diffusion and transport codes, obtaining reference solutions for stationary states with Monte Carlo codes, performing coupled 3D full core analyses in diffusion approximation and with other deterministic and also Monte Carlo transport codes, and implementing uncertainty and sensitivity analyses with the aim of propagating uncertainties through the whole calculation chain from fuel assembly, spectral and depletion calculations to coupled transient analyses. This calculation chain shall be applicable to light water reactors and also to innovative reactor concepts, and therefore has to be extensively validated with the help of benchmarks and critical experiments.

Biomedical applications of two- and three-dimensional deterministic radiation transport methods

International Nuclear Information System (INIS)

Nigg, D.W.

1992-01-01

Multidimensional deterministic radiation transport methods are routinely used in support of the Boron Neutron Capture Therapy (BNCT) Program at the Idaho National Engineering Laboratory (INEL). Typical applications of two-dimensional discrete-ordinates methods include neutron filter design, as well as phantom dosimetry. The epithermal-neutron filter for BNCT that is currently available at the Brookhaven Medical Research Reactor (BMRR) was designed using such methods. Good agreement between calculated and measured neutron fluxes was observed for this filter. Three-dimensional discrete-ordinates calculations are used routinely for dose-distribution calculations in three-dimensional phantoms placed in the BMRR beam, as well as for treatment planning verification for live canine subjects. Again, good agreement between calculated and measured neutron fluxes and dose levels is obtained

ZZ SAIL, Albedo Scattering Data Library for 3-D Monte-Carlo Radiation Transport in LWR Pressure Vessel

International Nuclear Information System (INIS)

1982-01-01

1 - Description of problem or function: Format: SAIL format; Number of groups: 23 neutron / 17 gamma-ray; Nuclides: Type 04 Concrete and Low Carbon Steel (A533B). Origin: Science Applications, Inc (SAI); Weighting spectrum: yes. SAIL is a library of albedo scattering data to be used in three-dimensional Monte Carlo codes to solve radiation transport problems specific to the reactor pressure vessel cavity region of a LWR. The library contains data for Type 04 Concrete and Low Carbon Steel (A533B). 2 - Method of solution: The calculation of the albedo data was perform- ed with a version of the discrete ordinates transport code DOT which treats the transport of neutrons, secondary gamma-rays and gamma- rays in one dimension, while maintaining the complete two-dimension- al treatment of the angular dependence

Monte Carlo 2000 Conference : Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications

CERN Document Server

Baräo, Fernando; Nakagawa, Masayuki; Távora, Luis; Vaz, Pedro

2001-01-01

This book focusses on the state of the art of Monte Carlo methods in radiation physics and particle transport simulation and applications, the latter involving in particular, the use and development of electron--gamma, neutron--gamma and hadronic codes. Besides the basic theory and the methods employed, special attention is paid to algorithm development for modeling, and the analysis of experiments and measurements in a variety of fields ranging from particle to medical physics.

Results and prospects of personnel protection against radiation in a low and medium level waste storage center

International Nuclear Information System (INIS)

Scheidhauer, J.; Lasseur, C.

1982-01-01

The national low- and intermediate-level waste storage center (CM) located near the Channel is presented, together with its history, the various regulations governing it and their incidence on its operation. A description is given of the radiation sources and workplaces to be found in this kind of waste storage center. The radiation protection problems associated with the respective workplaces are analysed: organization, prevention, collective and individual protection, dosimetry. Occupational radiation exposures from 1970 to 1980 are presented. The various means of reducing operating workers' exposures are discussed, especially the incidence of transportation [fr

Trend of surface solar radiation over Asia simulated by aerosol transport-climate model

Science.gov (United States)

Takemura, T.; Ohmura, A.

2009-12-01

Long-term records of surface radiation measurements indicate a decrease in the solar radiation between the 1950s and 1980s (“global dimming”), then its recovery afterward (“global brightening”) at many locations all over the globe [Wild, 2009]. On the other hand, the global brightening is delayed over the Asian region [Ohmura, 2009]. It is suggested that these trends of the global dimming and brightening are strongly related with a change in aerosol loading in the atmosphere which affect the climate change through the direct, semi-direct, and indirect effects. In this study, causes of the trend of the surface solar radiation over Asia during last several decades are analyzed with an aerosol transport-climate model, SPRINTARS. SPRINTARS is coupled with MIROC which is a general circulation model (GCM) developed by Center for Climate System Research (CCSR)/University of Tokyo, National Institute for Environmental Studies (NIES), and Frontier Research Center for Global Change (FRCGC) [Takemura et al., 2000, 2002, 2005, 2009]. The horizontal and vertical resolutions are T106 (approximately 1.1° by 1.1°) and 56 layers, respectively. SPRINTARS includes the transport, radiation, cloud, and precipitation processes of all main tropospheric aerosols (black and organic carbons, sulfate, soil dust, and sea salt). The model treats not only the aerosol mass mixing ratios but also the cloud droplet and ice crystal number concentrations as prognostic variables, and the nucleation processes of cloud droplets and ice crystals depend on the number concentrations of each aerosol species. Changes in the cloud droplet and ice crystal number concentrations affect the cloud radiation and precipitation processes in the model. Historical emissions, that is consumption of fossil fuel and biofuel, biomass burning, aircraft emissions, and volcanic eruptions are prescribed from database provided by the Aerosol Model Intercomparison Project (AeroCom) and the latest IPCC inventories

Supersonic Ionization Wave Driven by Radiation Transport in a Short-Pulse Laser-Produced Plasma

International Nuclear Information System (INIS)

Ditmire, T.; Gumbrell, E.T.; Smith, R.A.; Mountford, L.; Hutchinson, M.H.

1996-01-01

Through the use of an ultrashort (2ps) optical probe, we have time resolved the propagation of an ionization wave into solid fused silica. This ionization wave results when a plasma is created by the intense irradiation of a solid target with a 2ps laser pulse. We find that the velocity of the ionization wave is consistent with radiation driven thermal transport, exceeding the velocity expected from simple electron thermal conduction by nearly an order of magnitude. copyright 1996 The American Physical Society

Nuclear medicine radiation dosimetry

CERN Document Server

McParland, Brian J

2010-01-01

Complexities of the requirements for accurate radiation dosimetry evaluation in both diagnostic and therapeutic nuclear medicine (including PET) have grown over the past decade. This is due primarily to four factors: growing consideration of accurate patient-specific treatment planning for radionuclide therapy as a means of improving the therapeutic benefit, development of more realistic anthropomorphic phantoms and their use in estimating radiation transport and dosimetry in patients, design and use of advanced Monte Carlo algorithms in calculating the above-mentioned radiation transport and

Transport of radioactive materials

International Nuclear Information System (INIS)

1988-07-01

The norm which establishes the requirements of radiation protection and safety related to the transport of radioactive materials, aiming to keep a suitable control level of eventual exposure of personnels, materials and environment of ionizing radiation, including: specifications on radioactive materials for transport, selection of package type; specification of requirements of the design and assays of acceptance of packages; disposal related to the transport; and liability and administrative requirements, are presented. This norm is applied to: truckage, water carriage and air service; design, fabrication, assays and mantenaince of packages; preparation, despatching, handling, loading storage in transition and reception in the ultimate storage of packages; and transport of void packages which have been contained radioactive materials. (M.C.K.) [pt

Present and future problems of radiation shielding for maritime transport of nuclear spent fuels

International Nuclear Information System (INIS)

Ueki, K.; Nariyama, N.; Ohashi, A.

2000-01-01

The transport of spent fuels with casks began in September 1999 by the exclusive spent fuel transport vessel the 'Rokuei Maru'. The casks have been transported to the reprocessing plant at Rokkasho-village in Aomori Prefecture. The 'Rokuei Maru' is approximately 100 m-length, 16.5 m-width and 3,000 gross-tons. The 20 NFT casks can be loaded into 5 holds. At the present time, the NFT casks can carry spent fuels of up to 44,000 MWD/MTU. Serpentine concrete is employed as a neutron shields in the hatch covers, the bulkheads, and the house front of the accommodations except the wheelhouse. Polyethylene covers the side walls in each hold. The neutron shielding ability of serpentine concrete and polyethylene was investigated by a shielding experiment using a 252 Cf-neutron source. The shielding experiment was analyzed with the Monte Carlo code MCNP 4B. In the near future, on-board experiment will be carried out to measure the dose-equivalent rate distributions in the 'Rokuei Maru' and the measured data and the Monte Carlo analysis of it will establish the radiation safety of the ship. (author)

Variable order spherical harmonic expansion scheme for the radiative transport equation using finite elements

International Nuclear Information System (INIS)

Surya Mohan, P.; Tarvainen, Tanja; Schweiger, Martin; Pulkkinen, Aki; Arridge, Simon R.

2011-01-01

Highlights: → We developed a variable order global basis scheme to solve light transport in 3D. → Based on finite elements, the method can be applied to a wide class of geometries. → It is computationally cheap when compared to the fixed order scheme. → Comparisons with local basis method and other models demonstrate its accuracy. → Addresses problems encountered n modeling of light transport in human brain. - Abstract: We propose the P N approximation based on a finite element framework for solving the radiative transport equation with optical tomography as the primary application area. The key idea is to employ a variable order spherical harmonic expansion for angular discretization based on the proximity to the source and the local scattering coefficient. The proposed scheme is shown to be computationally efficient compared to employing homogeneously high orders of expansion everywhere in the domain. In addition the numerical method is shown to accurately describe the void regions encountered in the forward modeling of real-life specimens such as infant brains. The accuracy of the method is demonstrated over three model problems where the P N approximation is compared against Monte Carlo simulations and other state-of-the-art methods.

Impurity transport in internal transport barrier discharges on JET

International Nuclear Information System (INIS)

Dux, R.

2002-01-01

In JET plasmas with internal transport barrier (ITB) the behaviour of metallic and low-Z impurities (C, Ne) was investigated. In ITB discharges with reversed shear, the metallic impurities accumulate in cases with too strong peaking of the density profile, while the concentration of low-Z elements C and Ne is only mildly peaked. The accumulation might be so strong, that the central radiation approximately equals the central heating power followed by a radiative collapse of the transport barrier. The radial location with strong impurity gradients (convective barrier) was identified to be situated inside (not at!) the heat flux barrier. Calculations of neo-classical transport were performed for these discharges, including impurity-impurity collisions. It was found, that the observed Z-dependence of the impurity peaking and the location of the impurity 'barrier' can be explained with neo-classical transport. ITB discharges with monotonic shear show less inward convection and seem to be advantageous with respect to plasma purity. (author)

Intense electron-beam transport in the ion-focused regime through the collision-dominated regime

International Nuclear Information System (INIS)

Sanford, T.W.L.; Poukey, J.W.; Welch, D.R.; Mock, R.C.

1993-01-01

This paper reviews the transport of the 19-MeV, 700-kA, 25-ns Hermes-III electron beam in long gas cells filled with N 2 gas spanning six decades in pressure from 10 3 to ∼10 3 Torr. We show through measurements and theoretical analyses that the beam has two windows of stable transport: a low-pressure window (between ∼1 and ∼100 mTorr) that is dominated by propagation in the semi-collisionless IFR (ion-focused regime), and a high-pressure window (between ∼1 and ∼100 Torr) that is dominated by propagation in the resistive CDR (collision-dominated regime). In the CDR, 79±1.5% of the beam energy is transported over 11 m at 20 Torr. In the IFR, we show that intense radiation fields with controllable rise times and pulse widths can be generated on axis at a bremsstrahlung target. In summary, the measurements and analyses presented here provide a quantitative description of the Hermes-III beam transport over six decades in pressure

Synchrotron radiation. 4. Analyses of biological samples using synchrotron radiation. 3. Research on radiation damage to DNA using synchrotron radiation

International Nuclear Information System (INIS)

Takakura, Kaoru

1998-01-01

This review described how the synchrotron radiation (SR) is used to solve problems unknown hitherto in radiation biology. Historically, the target substance of UV light in bacterial death was suggested to be nucleic acid in 1930. Researches on the radiation damage to DNA were begun at around 1960 and have mainly used UV light, X-ray and γray. Soft X-ray and vacuum UV whose energy covering from several eV to scores of keV have not been used since UV and X-ray lack the energy of this range. This is one of reasons why detailed process leading to radiation-induced death, carcinogenicity and mutation has not been known hitherto. RS possesses wide range of energy, i.e., from UV to hard X-ray, of high intensity, which is helpful for studying the unknown problems. The RS studies were begun in nineteen-seventies. Those include the action spectrum studies and atomic target studies. In the former, the course of the effect, e.g., the mechanism of DNA double strand breakage, can be elucidated. In the latter, photon of known energy can be irradiated to the specified atom like phosphorus in DNA which elucidating the precise physicochemical process of the breakage. Use of RS in these studies is thought still meaningful in future. (K.H.) 62 refs

Establishing Sustainable Infrastructures for Education and Training in Radiation, Transport and Waste Safety: IAEA’s Approach to Support Member States

International Nuclear Information System (INIS)

Wheatley, John

2014-01-01

Summary: • IAEA General Conference has called upon MS to develop national strategies for education &training radiation, transport & waste safety; • IAEA has developed guidance, and is providing support to MSs; • IAEA Regional Training Centres are key partners with IAEA

North Atlantic Aerosol Properties for Radiative Impact Assessments. Derived from Column Closure Analyses in TARFOX and ACE-2

Science.gov (United States)

Russell, Philip A.; Bergstrom, Robert A.; Schmid, Beat; Livingston, John M.

2000-01-01

Aerosol effects on atmospheric radiative fluxes provide a forcing function that can change the climate in potentially significant ways. This aerosol radiative forcing is a major source of uncertainty in understanding the climate change of the past century and predicting future climate. To help reduce this uncertainty, the 1996 Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX) and the 1997 Aerosol Characterization Experiment (ACE-2) measured the properties and radiative effects of aerosols over the Atlantic Ocean. Both experiments used remote and in situ measurements from aircraft and the surface, coordinated with overpasses by a variety of satellite radiometers. TARFOX focused on the urban-industrial haze plume flowing from the United States over the western Atlantic, whereas ACE-2 studied aerosols over the eastern Atlantic from both Europe and Africa. These aerosols often have a marked impact on satellite-measured radiances. However, accurate derivation of flux changes, or radiative forcing, from the satellite measured radiances or retrieved aerosol optical depths (AODs) remains a difficult challenge. Here we summarize key initial results from TARFOX and ACE-2, with a focus on closure analyses that yield aerosol microphysical models for use in improved assessments of flux changes. We show how one such model gives computed radiative flux sensitivities (dF/dAOD) that agree with values measured in TARFOX and preliminary values computed for the polluted marine boundary layer in ACE-2. A companion paper uses the model to compute aerosol-induced flux changes over the North Atlantic from AVHRR-derived AOD fields.

Transport, charge exchange and loss of energetic heavy ions in the earth's radiation belts - Applicability and limitations of theory

Science.gov (United States)

Spjeldvik, W. N.

1981-01-01

Computer simulations of processes which control the relative abundances of ions in the trapping regions of geospace are compared with observations from discriminating ion detectors. Energy losses due to Coulomb collisions between ions and exospheric neutrals are considered, along with charge exchange losses and internal charge exchanges. The time evolution of energetic ion fluxes of equatorially mirroring ions under radial diffusion is modelled to include geomagnetic and geoelectric fluctutations. Limits to the validity of diffusion transport theory are discussed, and the simulation is noted to contain provisions for six ionic charge states and the source effect on the radiation belt oxygen ion distributions. Comparisons are made with ion flux data gathered on Explorer 45 and ISEE-1 spacecraft and results indicate that internal charge exchanges cause the radiation belt ion charge state to be independent of source charge rate characteristics, and relative charge state distribution is independent of the radially diffusive transport rate below the charge state redistribution zone.

Radiation transport Part B: Applications with examples

International Nuclear Information System (INIS)

Beutler, D.E.

1997-01-01

In the previous sections Len Lorence has described the need, theory, and types of radiation codes that can be applied to model the results of radiation effects tests or working environments for electronics. For the rest of this segment, the author will concentrate on the specific ways the codes can be used to predict device response or analyze radiation test results. Regardless of whether one is predicting responses in a working or test environment, the procedures are virtually the same. The same can be said for the use of 1-, 2-, or 3-dimensional codes and Monte Carlo or discrete ordinates codes. No attempt is made to instruct the student on the specifics of the code. For example, the author will not discuss the details, such as the number of meshes, energy groups, etc. that are appropriate for a discrete ordinates code. For the sake of simplicity, he will restrict himself to the 1-dimensional code CEPXS/ONELD. This code along with a wide variety of other radiation codes can be obtained form the Radiation Safety Information Computational Center (RSICC) for a nominal handling fee

The RAGE radiation-hydrodynamic code

International Nuclear Information System (INIS)

Gittings, Michael; Clover, Michael; Betlach, Thomas; Byrne, Nelson; Ranta, Dale; Weaver, Robert; Coker, Robert; Dendy, Edward; Hueckstaedt, Robert; New, Kim; Oakes, W Rob; Stefan, Ryan

2008-01-01

We describe RAGE, the 'radiation adaptive grid Eulerian' radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov solver, to which we have made significant improvements to increase the advection algorithm's robustness and to converge stiffnesses in the equation of state. Similarly, the radiation transport is a basic gray diffusion, but our treatment of the radiation-material coupling, wherein we converge nonlinearities in a novel manner to allow larger timesteps and more robust behavior, can be applied to any multi-group transport algorithm

Evaluation of doses during the handling and transport of radioactive wastes containers

International Nuclear Information System (INIS)

Kubik, I.; Kusovska, Z.; Hanusik, V.; Mrskova, A.; Kapisovsky, V.

2000-01-01

Radioactive waste products from the nuclear power plants (NPPs) must be isolated from contact with people for very long period of time. Low and intermediate-level waste will be disposed of in Slovakia in specially licensed Regional disposal facility which is located near the NPP Mochovce site. Radioactive waste accumulated in the Jaslovsk. Bohunice site, during the decommissioning process of the NPP A-1 and arising from the NPP V-1 and NPP V-2 operation, will be processed and shipped in standard concrete containers to the Mochovce Regional disposal facility. The treatment centre was build at the NPP Jaslovsk? Bohunice site which is in the trial operation now. It is supposed that radioactive waste containers will be transported by train from the treatment centre Jaslovsk? Bohunice to the site of Radioactive Waste Repository at Mochovce and by truck in the area of repository. To estimate the occupational radiation exposure during the transport the calculations of dose rates from the containers are necessary. The national regulations allow low level of radiation to emanate from the casks and containers. The maximum permissible volume radioactivity of wastes inside the container is limited in such a way that irradiation level should not exceed 2 mGy/h for the contact irradiation level and 0,1 mGy/h at 2-meter distance. MicroShield code was used to analyse shielding and assessing exposure from gamma radiation of containers to people. A radioactive source was conservatively modelled by homogenous mixture of radionuclides with concrete. Standard rectangular volume source and shield geometry is used in model calculations. The activities of the personnel during the transport and storage of containers are analysed and results of the evaluation of external dose rates and effective doses are described. (author)

Treatment of spices with ionizing radiation - chemical, organoleptical, microbiological and toxicological analyses. Pt. 1. Behandlung von Gewuerzen mit ionisierenden Strahlen - chemische, organoleptische, mikrobiologische und toxikologische Aspekte

Energy Technology Data Exchange (ETDEWEB)

Schuettler, C; Boegl, W

1984-01-01

In a study of the relevant literature the results of tests on 30 radiation treated spices were evaluated. The tests contain chemical, organoleptical, microbiological and toxicological analyses. Most of the spices were treated with gamma radiation from cobalt-60 sources with doses up to 60 kGy.

Application and further development of models for the final repository safety analyses on the clearance of radioactive materials for disposal. Final report; Anwendung und Weiterentwicklung von Modellen fuer Endlagersicherheitsanalysen auf die Freigabe radioaktiver Stoffe zur Deponierung. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Artmann, Andreas; Larue, Juergen; Seher, Holger; Weiss, Dietmar

2014-08-15

The project of application and further development of models for the final repository safety analyses on the clearance of radioactive materials for disposal is aimed to study the long-term safety using repository-specific simulation programs with respect to radiation exposure for different scenarios. It was supposed to investigate whether the 10 micro Sv criterion can be guaranteed under consideration of human intrusion scenarios. The report covers the following issues: selection and identification of models and codes and the definition of boundary conditions; applicability of conventional repository models for long-term safety analyses; modeling results for the pollutant release and transport and calculation of radiation exposure; determination of the radiation exposure.

PENGEOM-A general-purpose geometry package for Monte Carlo simulation of radiation transport in material systems defined by quadric surfaces

Science.gov (United States)

Almansa, Julio; Salvat-Pujol, Francesc; Díaz-Londoño, Gloria; Carnicer, Artur; Lallena, Antonio M.; Salvat, Francesc

2016-02-01

The Fortran subroutine package PENGEOM provides a complete set of tools to handle quadric geometries in Monte Carlo simulations of radiation transport. The material structure where radiation propagates is assumed to consist of homogeneous bodies limited by quadric surfaces. The PENGEOM subroutines (a subset of the PENELOPE code) track particles through the material structure, independently of the details of the physics models adopted to describe the interactions. Although these subroutines are designed for detailed simulations of photon and electron transport, where all individual interactions are simulated sequentially, they can also be used in mixed (class II) schemes for simulating the transport of high-energy charged particles, where the effect of soft interactions is described by the random-hinge method. The definition of the geometry and the details of the tracking algorithm are tailored to optimize simulation speed. The use of fuzzy quadric surfaces minimizes the impact of round-off errors. The provided software includes a Java graphical user interface for editing and debugging the geometry definition file and for visualizing the material structure. Images of the structure are generated by using the tracking subroutines and, hence, they describe the geometry actually passed to the simulation code.

On linear transport problems

International Nuclear Information System (INIS)

Ignatovich, V.K.

1989-01-01

The equations. governing the transport of radiation in plane media of finite thickness are formulated and solved in terms reflection and extintion of radiation inthe case of semi infinite media. 13 refs

Activation and Shielding Analyses in Support of the GUINEVERE Project

International Nuclear Information System (INIS)

Serikov, A.; Fischer, U.; Mercatali, L.; Baeten, P.; Vittiglio, G.

2008-01-01

The GUINEVERE facility (Generator of Uninterrupted Intense Neutrons at the lead Venus Reactor) must satisfy the nuclear safety criteria required by the Belgian safety authority to be licensed. The radiation dose and activation analyses for the nuclear safety assessment of the GUINEVERE project were performed at FZK. The concerted efforts of several European institutions were concentrated on the development and construction of a subcritical fast lead core based on the Venus water moderated reactor at the SCK-CEN site in Mol, Belgium. A Monte Carlo (MC) MCNP5 model was developed in accordance with the current design of the GUINEVERE fast lead core. The analytical MC method does not work for shielding analysis of the GUINEVERE building because of the large size of the rooms and thick concrete walls and floors. MC variance reduction techniques, such as particles splitting, Russian roulette, and point detectors were therefore applied. The JEFF-3.1 nuclear data library was used for radiation transport calculations. The activation analyses for the lead core and building materials were performed with the FISPACT-2005 inventory code and the EAF-2005 library. The neutron and photon dose rate maps were produced using MCNP track-length estimations, point detectors, and a mesh tally superimposed over the GUINEVERE geometry. The effects of D-D and D-T fusion neutron sources were estimated. (authors)

Activation and Shielding Analyses in Support of the GUINEVERE Project

Energy Technology Data Exchange (ETDEWEB)

Serikov, A.; Fischer, U.; Mercatali, L. [Association FZK-EURATOM, KIT, Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Baeten, P.; Vittiglio, G. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium)

2008-07-01

The GUINEVERE facility (Generator of Uninterrupted Intense Neutrons at the lead Venus Reactor) must satisfy the nuclear safety criteria required by the Belgian safety authority to be licensed. The radiation dose and activation analyses for the nuclear safety assessment of the GUINEVERE project were performed at FZK. The concerted efforts of several European institutions were concentrated on the development and construction of a subcritical fast lead core based on the Venus water moderated reactor at the SCK-CEN site in Mol, Belgium. A Monte Carlo (MC) MCNP5 model was developed in accordance with the current design of the GUINEVERE fast lead core. The analytical MC method does not work for shielding analysis of the GUINEVERE building because of the large size of the rooms and thick concrete walls and floors. MC variance reduction techniques, such as particles splitting, Russian roulette, and point detectors were therefore applied. The JEFF-3.1 nuclear data library was used for radiation transport calculations. The activation analyses for the lead core and building materials were performed with the FISPACT-2005 inventory code and the EAF-2005 library. The neutron and photon dose rate maps were produced using MCNP track-length estimations, point detectors, and a mesh tally superimposed over the GUINEVERE geometry. The effects of D-D and D-T fusion neutron sources were estimated. (authors)

Improved non-local electron thermal transport model for two-dimensional radiation hydrodynamics simulations

Science.gov (United States)

Cao, Duc; Moses, Gregory; Delettrez, Jacques

2015-08-01

An implicit, non-local thermal conduction algorithm based on the algorithm developed by Schurtz, Nicolai, and Busquet (SNB) [Schurtz et al., Phys. Plasmas 7, 4238 (2000)] for non-local electron transport is presented and has been implemented in the radiation-hydrodynamics code DRACO. To study the model's effect on DRACO's predictive capability, simulations of shot 60 303 from OMEGA are completed using the iSNB model, and the computed shock speed vs. time is compared to experiment. Temperature outputs from the iSNB model are compared with the non-local transport model of Goncharov et al. [Phys. Plasmas 13, 012702 (2006)]. Effects on adiabat are also examined in a polar drive surrogate simulation. Results show that the iSNB model is not only capable of flux-limitation but also preheat prediction while remaining numerically robust and sacrificing little computational speed. Additionally, the results provide strong incentive to further modify key parameters within the SNB theory, namely, the newly introduced non-local mean free path. This research was supported by the Laboratory for Laser Energetics of the University of Rochester.

Scheme for generating and transporting THz radiation to the X-ray experimental hall at the European XFEL

Energy Technology Data Exchange (ETDEWEB)

Decking, Winfried; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

2011-12-15

The design of a THz edge radiation source for the European XFEL is presented.We consider generation of THz radiation from the spent electron beam downstream of the SASE2 undulator in the electron beam dump area. In this way, the THz output must propagate at least for 250 meters through the photon beam tunnel to the experimental hall to reach the SASE2 X-ray hutches. We propose to use an open beam waveguide such as an iris guide as transmission line. In order to efficiently couple radiation into the iris transmission line, generation of the THz radiation pulse can be performed directly within the iris guide. The line transporting the THz radiation to the SASE2 X-ray hutches introduces a path delay of about 20 m. Since THz pump/X-ray probe experiments should be enabled, we propose to exploit the European XFEL baseline multi-bunch mode of operation, with 222 ns electron bunch separation, in order to cope with the delay between THz and X-ray pulses. We present start-to-end simulations for 1 nC bunch operation-parameters, optimized for THz pump/X-ray probe experiments.Detailed characterization of the THz and SASE X-ray radiation pulses is performed. Highly focused THz beams will approach the high field limit of 1 V/atomic size. (orig.)

Simulation of radiation transport using MCNP for a teletherapy machine; Simulacion del transporte de radiacion usando MCNP para una maquina de teleterapia

Energy Technology Data Exchange (ETDEWEB)

Flores O, F.E.; Mireles G, F.; Davila R, J.I.; Pinedo V, J.L.; Risorios M, C.; Lopez del Rio, H. [UAZ, Unidad Academica de Estudios Nucleares, 98068 Zacatecas (Mexico)

2008-07-01

The MCNP code is used to simulate the radiation transport taking as tools the transport physics of each particle, either photon, neutron or electron, and the generation of random numbers. Developed in the Los Alamos National Laboratory, this code has been used thoroughly with great success, because the results of the simulations are broadly validated with representative experiments. In the one present work the room of radiotherapy of the Institute Zacatecano of the Tumor it is simulated, located in the city of Zacatecas where one is Theratron 780C machine manufactured by MSD Nordion, with the purpose of estimating the contribution to the dose that would be received in different points of the structure, included three directly under the source. Three results of analytical calculations for points located at different distances from the source are presented, and they are compared against those obtained by the simulation. Its are also presented results for the simulation of 10 points more distributed around the source. (Author)

Effect Analysis on the Radiation Dose Rate of Nagasaki Atomic Bomb Survivors by Atmospheric Condition

Energy Technology Data Exchange (ETDEWEB)

Seo, Ji Sun; Kim, Jong Kyung [Hanyang University, Seoul (Korea, Republic of); Shin, Chang Ho [Innovative Technology Center for Radiation Safety, Seoul (Korea, Republic of); Kim, Do Heon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

The Dosimetry System 2002 (DS02) had been established to evaluate the radiation doses for the atomic bomb survivors in Hiroshima and Nagasaki. The radiation effects of neutrons and gamma-rays emitted from the atomic bombs detonated at both cities were analyzed, and two types of radiation transport codes (i.e., MCNP4C and DORT) were employed in their studies. It was specifically investigated for contribution of each type of radiations to total dose. However, it is insufficient to examine the effects by various environmental factors such as weather conditions, because their calculations were only performed under certain condition at the times of the bombings. In addition, the scope of them does not include acute radiation injury of the atomic bomb survivors in spite of important information for investigating hazard of unexpected radiation accident. Therefore, this study analyzed the contribution of primary and secondary effects (i.e., skyshine and groundshine) of neutrons emitted from the Nagasaki atomic bomb. These analyses were performed through a series of radiation transport calculations by using MCNPX 2.6.0 code with variations of atmospheric density. The acute radiation injury by prompt neutrons was also evaluated as a function of distance from the hypocenter, where hypocenter is the point on the ground directly beneath the epicenter which is the burst point of the bomb in air

Simulation of decay processes and radiation transport times in radioactivity measurements

Energy Technology Data Exchange (ETDEWEB)

García-Toraño, E., E-mail: e.garciatorano@ciemat.es [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Peyres, V. [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Bé, M.-M.; Dulieu, C.; Lépy, M.-C. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bldg 602, PC111, 91191 Gif-sur-Yvette Cedex (France); Salvat, F. [Facultat de Física (FQA and ICC), Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)

2017-04-01

The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

Spatially resolved synchrotron radiation induced X-ray fluorescence analyses of rare Rembrandt silverpoint drawings

International Nuclear Information System (INIS)

Reiche, I.; Radtke, M.; Berger, A.; Goerner, W.; Merchel, S.; Riesemeier, H.; Bevers, H.

2006-01-01

New analyses of a series of very rare silverpoint drawings that were executed by Rembrandt Harmensz. van Rijn (1606-1669) which are kept today in the Kupferstichkabinett (Museum of Prints and Drawings) of the State Museums of Berlin are reported here. Analysis of these drawings requires particular attention because the study has to be fully non-destructive and extremely sensitive. The metal alloy on the paper does not exceed some hundreds of μg/cm 2 . Therefore, synchrotron radiation induced X-ray fluorescence (SR-XRF) is - together with external micro-proton-induced X-ray emission - the only well-suited method for the analyses of metalpoint drawings. In some primary work, about 25 German and Flemish metalpoint drawings were investigated using spatially resolved SR-XRF analysis at the BAMline at BESSY. This study enlarges the existing French-German database of metalpoint drawings dating from the 15th and 16th centuries, as these Rembrandt drawings originate from the 17th century where this graphical technique was even rarer and already obsolete. It also illustrates how SR-XRF analysis can reinforce art historical assumptions on the dating of drawings and their connection. (orig.)

Application of the three-dimensional transport code to analysis of the neutron streaming experiment

International Nuclear Information System (INIS)

Chatani, K.; Slater, C.O.

1990-01-01

The neutron streaming through an experimental mock-up of a Clinch River Breeder Reactor (CRBR) prototypic coolant pipe chaseway was recalculated with a three-dimensional discrete ordinates code. The experiment was conducted at the Tower Shielding Facility at Oak Ridge National Laboratory in 1976 and 1977. The measurement of the neutron flux, using Bonner ball detectors, indicated nine orders of attenuation in the empty pipeway, which contained two 90-deg bends and was surrounded by concrete walls. The measurement data were originally analyzed using the DOT3.5 two-dimensional discrete ordinates radiation transport code. However, the results did not agree with measurement data at the bend because of the difficulties in modeling the three-dimensional configurations using two-dimensional methods. The two-dimensional calculations used a three-step procedure in which each of the three legs making the two 90-deg bends was a separate calculation. The experiment was recently analyzed with the TORT three-dimensional discrete ordinates radiation transport code, not only to compare the calculational results with the experimental results, but also to compare with results obtained from analyses in Japan using DOT3.5, MORSE, and ENSEMBLE, which is a three-dimensional discrete ordinates radiation transport code developed in Japan

Radiation transport calculations for the ANS [Advanced Neutron Source] beam tubes

International Nuclear Information System (INIS)

Engle, W.W. Jr.; Lillie, R.A.; Slater, C.O.

1988-01-01

The Advanced Neutron Source facility (ANS) will incorporate a large number of both radial and no-line-of-sight (NLS) beam tubes to provide very large thermal neutron fluxes to experimental facilities. The purpose of this work was to obtain comparisons for the ANS single- and split-core designs of the thermal and damage neutron and gamma-ray scalar fluxes in these beams tubes. For experimental locations far from the reactor cores, angular flux data are required; however, for close-in experimental locations, the scalar fluxes within each beam tube provide a credible estimate of the various signal to noise ratios. In this paper, the coupled two- and three-dimensional radiation transport calculations employed to estimate the scalar neutron and gamma-ray fluxes will be described and the results from these calculations will be discussed. 6 refs., 2 figs

Conceptual designs of radioactive canister transporters

International Nuclear Information System (INIS)

1978-02-01

This report covers conceptual designs of transporters for the vertical, horizontal, and inclined installation of canisters containing spent-fuel elements, high-level waste, cladding waste, and intermediate-level waste (low-level waste is not discussed). Included in the discussion are cask concepts; transporter vehicle designs; concepts for mechanisms for handling and manipulating casks, canisters, and concrete plugs; transporter and repository operating cycles; shielding calculations; operator radiation dosages; radiation-resistant materials; and criteria for future design efforts

Radiation protection to firemen

International Nuclear Information System (INIS)

Almeida, E.S. de.

1985-01-01

The basic Knowledge about ionizing radiation oriented for firemen, are presented. The mainly damage and effects caused by radiation exposure as well as the method of radiation protection are described in simple words. The action to be taken in case of fire involving radiation such as vehicles transporting radioactive materials are emphasized. (author)

Analysis of the pool critical assembly benchmark using raptor-M3G, a parallel deterministic radiation transport code - 289

International Nuclear Information System (INIS)

Fischer, G.A.

2010-01-01

The PCA Benchmark is analyzed using RAPTOR-M3G, a parallel SN radiation transport code. A variety of mesh structures, angular quadrature sets, cross section treatments, and reactor dosimetry cross sections are presented. The results show that RAPTOR-M3G is generally suitable for PWR neutron dosimetry applications. (authors)

Computer codes in nuclear safety, radiation transport and dosimetry; Les codes de calcul en radioprotection, radiophysique et dosimetrie

Energy Technology Data Exchange (ETDEWEB)

Bordy, J M; Kodeli, I; Menard, St; Bouchet, J L; Renard, F; Martin, E; Blazy, L; Voros, S; Bochud, F; Laedermann, J P; Beaugelin, K; Makovicka, L; Quiot, A; Vermeersch, F; Roche, H; Perrin, M C; Laye, F; Bardies, M; Struelens, L; Vanhavere, F; Gschwind, R; Fernandez, F; Quesne, B; Fritsch, P; Lamart, St; Crovisier, Ph; Leservot, A; Antoni, R; Huet, Ch; Thiam, Ch; Donadille, L; Monfort, M; Diop, Ch; Ricard, M

2006-07-01

The purpose of this conference was to describe the present state of computer codes dedicated to radiation transport or radiation source assessment or dosimetry. The presentations have been parted into 2 sessions: 1) methodology and 2) uses in industrial or medical or research domains. It appears that 2 different calculation strategies are prevailing, both are based on preliminary Monte-Carlo calculations with data storage. First, quick simulations made from a database of particle histories built though a previous Monte-Carlo simulation and secondly, a neuronal approach involving a learning platform generated through a previous Monte-Carlo simulation. This document gathers the slides of the presentations.

A discussion for alteration of the radiation issues based on the clipping analyses of radiation articles reported in Korea

International Nuclear Information System (INIS)

Kim, Joo Yeon; Youn, Dol Mi; Yoo, Ji Yup; Park, Tai Jin

2016-01-01

Radiation accidents having occurred in recent containing the accident in Fukushima nuclear power plants of Japan were resulted to the increase in some public concern, anxiety and confusion for radiation or nuclear safety. The public anxiety for radiation is not being decreased though the announcements done in radiation research institutes in Korea. Therefore, this study aims at providing an effective system for radiation publicity to the public members by the clipping analysis for the radiation articles reported in the media. And, the relation between those radiation issues and the radiation perception to the public members is analyzed. The radiation articles reported by them in 2013 and 2014 have been collected, and they are then classified with the article characteristic, field and tendency. Classified articles have been reviewed by dividing as two year. The 210 articles have been compared for their tendencies, characteristics and fields by year reported, and their characteristic comparison by reported year are then reviewed. Though the frequency that the radiological accidents have occurred in worldwide is far low compared to the accidental frequencies occurred in the general industrial fields, the radiation perception is being still deteriorated because of its special problem, which is defined as exposure, contamination or radioactivity, about radiation. The basic principles for radiation communication were suggested for preventing some unnecessary misunderstanding due to the variation of understanding for radiation issues. It is necessary to perform a variety of strategies for the publicity in improving the radiation perception, to build a relationship with the press or the media and then to consistently interact with them. Radiation communication must be performed by radiation experts or complete charge department, and must be consistently performed and be taken predictable patterns

A discussion for alteration of the radiation issues based on the clipping analyses of radiation articles reported in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Joo Yeon; Youn, Dol Mi; Yoo, Ji Yup; Park, Tai Jin [Korean Association for Radiation Application, Seoul (Korea, Republic of)

2016-06-15

Radiation accidents having occurred in recent containing the accident in Fukushima nuclear power plants of Japan were resulted to the increase in some public concern, anxiety and confusion for radiation or nuclear safety. The public anxiety for radiation is not being decreased though the announcements done in radiation research institutes in Korea. Therefore, this study aims at providing an effective system for radiation publicity to the public members by the clipping analysis for the radiation articles reported in the media. And, the relation between those radiation issues and the radiation perception to the public members is analyzed. The radiation articles reported by them in 2013 and 2014 have been collected, and they are then classified with the article characteristic, field and tendency. Classified articles have been reviewed by dividing as two year. The 210 articles have been compared for their tendencies, characteristics and fields by year reported, and their characteristic comparison by reported year are then reviewed. Though the frequency that the radiological accidents have occurred in worldwide is far low compared to the accidental frequencies occurred in the general industrial fields, the radiation perception is being still deteriorated because of its special problem, which is defined as exposure, contamination or radioactivity, about radiation. The basic principles for radiation communication were suggested for preventing some unnecessary misunderstanding due to the variation of understanding for radiation issues. It is necessary to perform a variety of strategies for the publicity in improving the radiation perception, to build a relationship with the press or the media and then to consistently interact with them. Radiation communication must be performed by radiation experts or complete charge department, and must be consistently performed and be taken predictable patterns.

The RAGE radiation-hydrodynamic code

Energy Technology Data Exchange (ETDEWEB)

Gittings, Michael; Clover, Michael; Betlach, Thomas; Byrne, Nelson; Ranta, Dale [Science Applications International Corp. MS A-1, 10260 Campus Point Drive, San Diego, CA 92121 (United States); Weaver, Robert; Coker, Robert; Dendy, Edward; Hueckstaedt, Robert; New, Kim; Oakes, W Rob [Los Alamos National Laboratory, MS T087, PO Box 1663, Los Alamos, NM 87545 (United States); Stefan, Ryan [TaylorMade-adidas Golf, 5545 Fermi Court, Carlsbad, CA 92008-7324 (United States)], E-mail: michael.r.clover@saic.com

2008-10-01

We describe RAGE, the 'radiation adaptive grid Eulerian' radiation-hydrodynamics code, including its data structures, its parallelization strategy and performance, its hydrodynamic algorithm(s), its (gray) radiation diffusion algorithm, and some of the considerable amount of verification and validation efforts. The hydrodynamics is a basic Godunov solver, to which we have made significant improvements to increase the advection algorithm's robustness and to converge stiffnesses in the equation of state. Similarly, the radiation transport is a basic gray diffusion, but our treatment of the radiation-material coupling, wherein we converge nonlinearities in a novel manner to allow larger timesteps and more robust behavior, can be applied to any multi-group transport algorithm.

Anti-diffusive radiation flow in the cooling layer of a radiating shock

International Nuclear Information System (INIS)

McClarren, Ryan G.; Paul Drake, R.

2010-01-01

This paper shows that for systems with optically thin, hot layers, such as those that occur in radiating shocks, radiation will flow uphill: radiation will flow from low to high radiation energy density. These are systems in which the angular distribution of the radiation intensity changes rapidly in space, and in which the radiation in some region has a pancaked structure, whose effect on the mean intensity will be much larger than the effect on the scalar radiation pressure. The salient feature of the solution to the radiative transfer equation in these circumstances is that the gradient of the radiation energy density is in the same direction as the radiation flux, i.e. radiation energy is flowing uphill. Such an anti-diffusive flow of energy cannot be captured by a model where the spatial variation of the Eddington factor is not accounted for, as in flux-limited diffusion models or the P 1 equations. The qualitative difference between the two models leads to a monotonic mean intensity for the diffusion model whereas the transport mean intensity has a global maximum in the hot layer. Mathematical analysis shows that the discrepancy between the diffusion model and the transport solution is due to an approximation of exponential integrals using a simple exponential.

Radiation protection forum

International Nuclear Information System (INIS)

Cabral, W.

2010-01-01

The National Director of the Nuclear Regulatory Authority and Radiation Protection of Uruguay in the first forum for radiation protection set out the following themes: activity of regulatory body, radiation safety, physical security, safeguards, legal framework, committed substantive program, use of radiation, risks and benefits, major sources of radiation, the national regulatory framework, national inventory of sources, inspections, licensing, import and export of sources control , radioactive transport, materials safety, agreements, information and teaching, radiological emergencies and prompt response.

Effects of the Mt. Pinatubo eruption on the chemistry, radiative, and transport processes in the stratosphere

International Nuclear Information System (INIS)

Wuebbles, D.J.; Kinnison, D.E.; Grant, K.E.; Connell, P.S.

1992-09-01

Volcanic eruptions can significantly impact trace gas distribution in the upper troposphere and lower stratosphere. Massive eruptions, produce large quantities of SO 2 , H 2 O, chlorine compounds, and particulates. Modeling the effects of these impulsive increases in traces gases and comparing the results with observations from ground and satellite measurements provide unique opportunities to test current multi-dimensional chemical-radiative-transport models of the global atmosphere. Since these models are currently being used in assessment studies for future anthropogenic emissions of trace gases quantitative understanding of the accuracy of these models is essential. In this study, we have used observed data from the Stratospheric Aerosol and Gas Experiment II (SAGE II) aboard the Earth Radiation Budget Satellite (ERBS) to realistically represent both the time dependent change in aerosol surface area density and wavelength dependent extinction values from the Mt. Pinatubo Eruption. Increases in the aerosol loading increase the rate of important heterogeneous chemical reactions converting odd nitrogen in both ClONO 2 and N 2 O 5 to HNO 3 . Radiative effects of increases aerosol optical thickness include changes to net radiative heating rates and to actinic fluxes. Changes to heating rates will indirectly change chemical reaction rates via changes in atmospheric temperatures. changes in actinic fluxes will directly modify photodissociation rates

Radiation transport benchmarks for simple geometries with void regions using the spherical harmonics method

International Nuclear Information System (INIS)

Kobayashi, K.

2009-01-01

In 2001, an international cooperation on the 3D radiation transport benchmarks for simple geometries with void region was performed under the leadership of E. Sartori of OECD/NEA. There were contributions from eight institutions, where 6 contributions were by the discrete ordinate method and only two were by the spherical harmonics method. The 3D spherical harmonics program FFT3 by the finite Fourier transformation method has been improved for this presentation, and benchmark solutions for the 2D and 3D simple geometries with void region by the FFT2 and FFT3 are given showing fairly good accuracy. (authors)

Comparison of the results of radiation transport calculation obtained by means of different programs

International Nuclear Information System (INIS)

Gorbatkov, D.V.; Kruchkov, V.P.

1995-01-01

Verification of calculational results of radiation transport, obtained by the known, programs and constant libraries (MCNP+ENDF/B, ANISN+HILO, FLUKA92) by means of their comparison with the precision results calculations through ROZ-6N+Sadko program constant complex and with experimental data, is carried out. Satisfactory agreement is shown with the MCNP+ENDF/B package data for the energy range of E<14 MeV. Analysis of the results derivations, obtained trough the ANISN-HILO package for E<400 MeV and the FLUKA92 programs of E<200 GeV is carried out. 25 refs., 12 figs., 3 tabs

Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols

Energy Technology Data Exchange (ETDEWEB)

Srivastava, A.K. [Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi (India); Ram, K. [Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi (India); Singh, Sachchidanand, E-mail: ssingh@nplindia.org [Radio and Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi (India); Kumar, Sanjeev [Radio and Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi (India); Tiwari, S. [Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi (India)

2015-01-01

The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (∼ 2000 m amsl) in central Himalaya over a period of more than two years (February 2006–May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (AOD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 ± 5 Wm{sup −2}) and high values of corresponding heating rate (0.80 ± 0.14 Kday{sup −1}) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from − 2 to + 14 Wm{sup −2} and from − 3 to − 50 Wm{sup −2} at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm{sup −2} resulting in a heating rate of 0.1–1.8 Kday{sup −1}. - Highlights: • Aerosol chemical and optical properties at Manora Peak, in central Himalaya, were significantly affected by dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. • Elevated AOD and lower SSA values were observed at Manora Peak during summer. • Enhancement in absorbing aerosols was observed during summer. • Large aerosol radiative forcing and heating rate was observed

Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols

International Nuclear Information System (INIS)

Srivastava, A.K.; Ram, K.; Singh, Sachchidanand; Kumar, Sanjeev; Tiwari, S.

2015-01-01

The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (∼ 2000 m amsl) in central Himalaya over a period of more than two years (February 2006–May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (AOD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 ± 5 Wm −2 ) and high values of corresponding heating rate (0.80 ± 0.14 Kday −1 ) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from − 2 to + 14 Wm −2 and from − 3 to − 50 Wm −2 at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm −2 resulting in a heating rate of 0.1–1.8 Kday −1 . - Highlights: • Aerosol chemical and optical properties at Manora Peak, in central Himalaya, were significantly affected by dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. • Elevated AOD and lower SSA values were observed at Manora Peak during summer. • Enhancement in absorbing aerosols was observed during summer. • Large aerosol radiative forcing and heating rate was observed over the station in the

Accounting for beta-particle energy loss to cortical bone via paired-image radiation transport (PIRT)

International Nuclear Information System (INIS)

Shah, Amish P.; Rajon, Didier A.; Patton, Phillip W.; Jokisch, Derek W.; Bolch, Wesley E.

2005-01-01

Current methods of skeletal dose assessment in both medical physics (radionuclide therapy) and health physics (dose reconstruction and risk assessment) rely heavily on a single set of bone and marrow cavity chord-length distributions in which particle energy deposition is tracked within an infinite extent of trabecular spongiosa, with no allowance for particle escape to cortical bone. In the present study, we introduce a paired-image radiation transport (PIRT) model which provides a more realistic three-dimensional (3D) geometry for particle transport in the skeletal site at both microscopic and macroscopic levels of its histology. Ex vivo CT scans were acquired of the pelvis, cranial cap, and individual ribs excised from a 66-year male cadaver (BMI of 22.7 kg m -2 ). For the three skeletal sites, regions of trabecular spongiosa and cortical bone were identified and segmented. Physical sections of interior spongiosa were taken and subjected to microCT imaging. Voxels within the resulting microCT images were then segmented and labeled as regions of bone trabeculae, endosteum, active marrow, and inactive marrow through application of image processing algorithms. The PIRT methodology was then implemented within the EGSNRC radiation transport code whereby electrons of various initial energies are simultaneously tracked within both the ex vivo CT macroimage and the CT microimage of the skeletal site. At initial electron energies greater than 50-200 keV, a divergence in absorbed fractions to active marrow are noted between PIRT model simulations and those estimated under existing techniques of infinite spongiosa transport. Calculations of radionuclide S values under both methodologies imply that current chord-based models may overestimate the absorbed dose to active bone marrow in these skeletal sites by 0% to 27% for low-energy beta emitters ( 33 P, 169 Er, and 177 Lu), by ∼4% to 49% for intermediate-energy beta emitters ( 153 Sm, 186 Re, and 89 Sr), and by ∼14% to

Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines; Anwendung der Inter-Line PCR zur Analyse von genomischen Veraenderungen in strahlentransformierten Saeugerzellinien

Energy Technology Data Exchange (ETDEWEB)

Leibhard, S.; Smida, J. [Muenchen Univ. (Germany). Strahlenbiologisches Inst.; Eckardt-Schupp, F.; Hieber, L. [GSF-Inst. fuer Strahlenbiologie, Oberschleissheim (Germany)

1996-12-31

Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique - the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.) [Deutsch] Repetitive DNA-Sequenzen der LINE-Familie, die weit verbreitet im Genom von Saeugerzellen vorkommen, koennen durch Exposition mit ionisierender Strahlung aktiviert und veraendert werden [1]. Durch eine Neu- bzw. Reintegration an anderen Positionen im Genom kann es zu bedeutenden Veraenderungen im Genom der Zelle kommen. Die Expression von Genen, die bei den Prozessen der Zelltransformation bzw. der Karzinogenese beteiligt sind, kann dadurch veraendert werden [2, 3]. Mithilfe der von uns entwickelten Inter-LINE PCR und der anschliessenden Analyse der veraenderten Produktmuster nach gelelektrophoretischer Auftrennung koennen solche `genomic rearrangements` unter Beteiligung von LINE-Elementen untersucht und naeher charakterisiert werden. Durch Klonierung und Sequenzierung transformations- bzw. tumorspezifischer PCR-Produkte sollte es moeglich sein Tumormarker fuer diagnostische Zwecke zu entwickeln. Die Methode wurde fuer die Analyse von Zellen des Syrischen Hamster aufgebaut, sie ist jedoch universell fuer alle Saeuger anwendbar. (orig.)

Recommendations for computer code selection of a flow and transport code to be used in undisturbed vadose zone calculations for TWRS immobilized wastes environmental analyses

International Nuclear Information System (INIS)

VOOGD, J.A.

1999-01-01

An analysis of three software proposals is performed to recommend a computer code for immobilized low activity waste flow and transport modeling. The document uses criteria restablished in HNF-1839, ''Computer Code Selection Criteria for Flow and Transport Codes to be Used in Undisturbed Vadose Zone Calculation for TWRS Environmental Analyses'' as the basis for this analysis

Electron transport calculations with biomedical and environmental applications: [Progress report, FY 1987

International Nuclear Information System (INIS)

1987-01-01

This project investigated radiation interactions with matter and radiation transport in bulk media, to generate basic radiological physics information. Applications include biomedical radiation dosimetry, the assessment of radiation hazards in nuclear technology, and modeling of biological radiation action. This work included the development of transport-theoretic methods, the compilation and critical evaluation of the underlying single-scattering cross sections, and the application of the transport methods to radiological physics problems. 7 refs

ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

Directory of Open Access Journals (Sweden)

Ali Payıdar AKGÜNGÖR

2004-03-01

Full Text Available Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properties. Every transportation system has advantages and disadvantages over each other. Therefore, comprehensive plans for future periods have to be prepared and how the sources of the country should be reasonably distributed among transportation systems must be investigated. Also, transportation plans have to be prepared to get coordinated operations among transportation systems while great investments are instituted in the entire country. There is no doubt that it is possible with combined transportation instead of concentration on one transportation system. Transportation policies in Turkey should be questioned since the level of highway transportation usage reaches to 95 % and level of sea transportation usage drops to less than 1 % in spite of being surrounded with sea in three sides of our land. In this paper, transportation systems and transportation policies in Turkey are evaluated in general and problems are analysed. Proposals are presented for the solutions of these problems.

Accelerator and radiation physics

CERN Document Server

Basu, Samita; Nandy, Maitreyee

2013-01-01

"Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

Non-Equilibrium Thermodynamic Analysis of Double Diffusive, Nanofluid Forced Convection in Catalytic Microreactors with Radiation Effects

Directory of Open Access Journals (Sweden)

Lilian Govone

2017-12-01

Full Text Available This paper presents a theoretical investigation of the second law performance of double diffusive forced convection in microreactors with the inclusion of nanofluid and radiation effects. The investigated microreactors consist of a single microchannel, fully filled by a porous medium. The transport of heat and mass are analysed by including the thick walls and a first order, catalytic chemical reaction on the internal surfaces of the microchannel. Two sets of thermal boundary conditions are considered on the external surfaces of the microchannel; (1 constant temperature and (2 constant heat flux boundary condition on the lower wall and convective boundary condition on the upper wall. The local thermal non-equilibrium approach is taken to thermally analyse the porous section of the system. The mass dispersion equation is coupled with the transport of heat in the nanofluid flow through consideration of Soret effect. The problem is analytically solved and illustrations of the temperature fields, Nusselt number, total entropy generation rate and performance evaluation criterion (PEC are provided. It is shown that the radiation effect tends to modify the thermal behaviour within the porous section of the system. The radiation parameter also reduces the overall temperature of the system. It is further demonstrated that, expectedly, the nanoparticles reduce the temperature of the system and increase the Nusselt number. The total entropy generation rate and consequently PEC shows a strong relation with radiation parameter and volumetric concentration of nanoparticles.

Ionizing radiation effects in Acai oil analysed by gas chromatography coupled to mass spectrometry technique

International Nuclear Information System (INIS)

Valli, Felipe; Fernandes, Carlos Eduardo; Moura, Sergio; Machado, Ana Carolina; Furasawa, Helio Akira; Pires, Maria Aparecida Faustino; Bustillos, Oscar Vega

2007-01-01

The Acai fruit is a well know Brazilian seed plant used in large scale as a source of feed stock, specially in the Brazilian North-east region. The Acai oil is use in many purposes from fuel sources to medicine. The scope of this paper is to analyzed the chemical structures modification of the acai oil after the ionizing radiation. The radiation were set in the range of 10 to 25 kGy in the extracted Acai oil. The analyses were made by gas chromatography coupled to mass spectrometry techniques. A GC/MS Shimatzu QP-5000 equipped with 30 meters DB-5 capillary column with internal diameter of 0.25 mm and 0.25 μm film thickness was used. Helium was used as carried gas and gave a column head pressure of 12 p.s.i. (1 p.s.i. = 6894.76 Pa) and an average flux of 1 ml/min. The temperature program for the GC column consisted of a 4-minutes hold at 75 deg C, a 15 deg C /min ramp to 200 deg C, 8 minutes isothermal. 20 deg C/min ramp to 250 deg C, 2 minutes isothermal. The extraction of the fatty acids was based on liquid-liquid method using chloroform as solvent. The chromatograms resulted shows the presences of the oleic acid and others fatty acids identify by the mass spectra library (NIST-92). The ionization radiation deplete the fatty acids presents in the Acai oil. Details on the chemical qualitative analytical is present as well in this work. (author)

Nuclear transport

International Nuclear Information System (INIS)

Anon.

2003-01-01

During january and february 2003, a unique event concerning nuclear transport was reported and rated 1 on the INES scale. This event concerns the absence of a maintenance operation on a shipping cask. This shipping cask was used for several years for nuclear transport inside La-hague site before being re-assigned to transport on public thoroughfare. The re-assignment of the cask should have been preceded and conditioned by a maintenance operation whose purpose is to check the efficiency of its radiation shield. During this period 2 on-site inspections concerning the transport of nuclear materials were performed. (A.C.)

Radiation dose evaluation for hypothetical accident with transport package containing Iridium-192 source

International Nuclear Information System (INIS)

Trontl, K.; Bace, M.; Pevec, D.

2002-01-01

The aim of this paper is to evaluate dose rates for a hypothetical accident with transport package containing Iridium-192 source and to design additional shielding necessary for the safe unloading of the container, assuming that during the unloading process the whole contents of a radioactive source is unshielded and that the operation is going to take place at the site where a working area exists in the vicinity of the unloading location. Based on the calculated radiation dose rates, a single arrangement of the additional concrete shields necessary for reduction of the gamma dose rates to the permitted level is proposed. The proposed solution is optimal considering safety on one hand and costs on the other.(author)

Radioactive materials transport

International Nuclear Information System (INIS)

Talbi, B.

1996-01-01

The development of peaceful applications of nuclear energy results in the increase of transport operations of radioactive materials. Therefore strong regulations on transport of radioactive materials turns out to be a necessity in Tunisia. This report presents the different axes of regulations which include the means of transport involved, the radiation protection of the carriers, the technical criteria of security in transport, the emergency measures in case of accidents and penalties in case of infringement. (TEC). 12 refs., 1 fig

Radiation regulation

International Nuclear Information System (INIS)

Braithwaite, J.; Grabosky, P.

1985-01-01

The five main areas of radiation regulation considered are radiation exposure in the mining of uranium and other minerals, exposure in the use of uranium in nuclear reactors, risks in the transport of radioactive materials and hazards associated with the disposal of used materials. In Australia these problems are regulated by mines departments, the Australian Atomic Energy Commission and radiation control branches in state health departments. Each of these instutional areas of regulation is examined

Suggestions of radiation protection instruments in ships used for transporting spent fuel elements from nuclear power plants to central stores and further to fuel reprocessing plants

International Nuclear Information System (INIS)

Warenmo, G.

1979-01-01

Some radiation protection measures are necessary in ships which will be used for transporting spent fuel elements from nuclear power plants to central stores and further to fuel reprocessing plants in order to protect the crew from unnecessarily high radiation doses and to ensure that not allowable values occur. Such measures are discussed in this report as well as suitable radiation protection instruments for such ships. (E.R.)

IAEA education and training in radiation protection, transport and waste safety-status and new developments for sustainability

International Nuclear Information System (INIS)

Sadagopan, G.; Mrabit, K.; Wheatley, J.

2008-01-01

IAEA 's education and training activities in radiation, transport and waste safety follow the IAEA vision, strategy and resolutions of its annual General Conferences and reflect the latest IAEA standards and guidance. IAEA prepared a Strategic Approach to Education and Training in Radiation and Waste Safety (Strategy on Education and Training) aiming at establishing, by 2010, sustainable education and training programmes in Member States, which was endorsed by the GC(45)/RES/10C in 2001. In implementing the strategy, IAEA is organising training events at the regional level and assisting the Member States at the national level by providing them the exemplary quality of training material developed at the IAEA. This work will continue ensuring its completeness in all areas of radiation safety. An Inter Centre Network between the Agency and regional, collaborating national training centres is established to facilitate information exchange, improve communication and dissemination of training material. There is a challenge to enhance the technical capability of the Member States to reach sustainability. This is intended through organising number of Train the Trainers events to develop a pool of qualified trainers. The new developments include establishing E-learning, developing a syllabus for training of Radiation Protection Officers and training materials, information materials for radiation workers. These are aimed at assisting Member States attain self sustainability. (author)

Modelling of aircrew radiation exposure during solar particle events

Science.gov (United States)

Al Anid, Hani Khaled

In 1990, the International Commission on Radiological Protection recognized the occupational exposure of aircrew to cosmic radiation. In Canada, a Commercial and Business Aviation Advisory Circular was issued by Transport Canada suggesting that action should be taken to manage such exposure. In anticipation of possible regulations on exposure of Canadian-based aircrew in the near future, an extensive study was carried out at the Royal Military College of Canada to measure the radiation exposure during commercial flights. The radiation exposure to aircrew is a result of a complex mixed-radiation field resulting from Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). Supernova explosions and active galactic nuclei are responsible for GCRs which consist of 90% protons, 9% alpha particles, and 1% heavy nuclei. While they have a fairly constant fluence rate, their interaction with the magnetic field of the Earth varies throughout the solar cycles, which has a period of approximately 11 years. SEPs are highly sporadic events that are associated with solar flares and coronal mass ejections. This type of exposure may be of concern to certain aircrew members, such as pregnant flight crew, for which the annual effective dose is limited to 1 mSv over the remainder of the pregnancy. The composition of SEPs is very similar to GCRs, in that they consist of mostly protons, some alpha particles and a few heavy nuclei, but with a softer energy spectrum. An additional factor when analysing SEPs is the effect of flare anisotropy. This refers to the way charged particles are transported through the Earth's magnetosphere in an anisotropic fashion. Solar flares that are fairly isotropic produce a uniform radiation exposure for areas that have similar geomagnetic shielding, while highly anisotropic events produce variable exposures at different locations on the Earth. Studies of neutron monitor count rates from detectors sharing similar geomagnetic shielding properties

The energy logistic model for analyses of transportation- and energy systems; Energilogistikmodell foer systemberaekningar av transport- och energifoersoerjningssystem

Energy Technology Data Exchange (ETDEWEB)

Blinge, M

1995-05-01

The Energy Logistic Model has been improved to become a tool for analysis of all production processes, transportation systems and systems including several energy users and several fuels. Two cases were studied. The first case deals with terminal equipment for inter modal transport systems and the second case deals with diesel fuelled trucks, cranes and machines in the Goeteborg area. In both cases, the environmental improvements of the city air quality are analyzed when natural gas is substituted for diesel oil. The comparison between inter modal transport and road haulage shows that the environmental impacts from the operations at the terminal are limited, and that the potential for environmental benefits when using inter modal transport is improving with the transportation distance. The choice of electricity production system is of great importance when calculating the environmental impact from railway traffic in the total analysis of the transportation system. 13 refs, 27 tabs

Monte Carlo radiation transport: A revolution in science

International Nuclear Information System (INIS)

Hendricks, J.

1993-01-01

When Enrico Fermi, Stan Ulam, Nicholas Metropolis, John von Neuman, and Robert Richtmyer invented the Monte Carlo method fifty years ago, little could they imagine the far-flung consequences, the international applications, and the revolution in science epitomized by their abstract mathematical method. The Monte Carlo method is used in a wide variety of fields to solve exact computational models approximately by statistical sampling. It is an alternative to traditional physics modeling methods which solve approximate computational models exactly by deterministic methods. Modern computers and improved methods, such as variance reduction, have enhanced the method to the point of enabling a true predictive capability in areas such as radiation or particle transport. This predictive capability has contributed to a radical change in the way science is done: design and understanding come from computations built upon experiments rather than being limited to experiments, and the computer codes doing the computations have become the repository for physics knowledge. The MCNP Monte Carlo computer code effort at Los Alamos is an example of this revolution. Physicians unfamiliar with physics details can design cancer treatments using physics buried in the MCNP computer code. Hazardous environments and hypothetical accidents can be explored. Many other fields, from underground oil well exploration to aerospace, from physics research to energy production, from safety to bulk materials processing, benefit from MCNP, the Monte Carlo method, and the revolution in science

Estimating DoD Transportation Spending: Analyses of Contract and Payment Transactions

National Research Council Canada - National Science Library

Moore, Nancy Y; Chenoweth, Mary E; Reardon, Elaine; Grammich, Clifford A; Bullock, Arthur M; Mele, Judith D; Kofner, Aaron; Unger, Eric J

2007-01-01

.... This analysis of combined individual contracting action report (DD350) and PowerTrack (PT) data indicates that DoD has additional opportunities to leverage transportation spending, particularly where it uses tenders to purchase transportation services...

Improved non-local electron thermal transport model for two-dimensional radiation hydrodynamics simulations

International Nuclear Information System (INIS)

Cao, Duc; Moses, Gregory; Delettrez, Jacques

2015-01-01

An implicit, non-local thermal conduction algorithm based on the algorithm developed by Schurtz, Nicolai, and Busquet (SNB) [Schurtz et al., Phys. Plasmas 7, 4238 (2000)] for non-local electron transport is presented and has been implemented in the radiation-hydrodynamics code DRACO. To study the model's effect on DRACO's predictive capability, simulations of shot 60 303 from OMEGA are completed using the iSNB model, and the computed shock speed vs. time is compared to experiment. Temperature outputs from the iSNB model are compared with the non-local transport model of Goncharov et al. [Phys. Plasmas 13, 012702 (2006)]. Effects on adiabat are also examined in a polar drive surrogate simulation. Results show that the iSNB model is not only capable of flux-limitation but also preheat prediction while remaining numerically robust and sacrificing little computational speed. Additionally, the results provide strong incentive to further modify key parameters within the SNB theory, namely, the newly introduced non-local mean free path. This research was supported by the Laboratory for Laser Energetics of the University of Rochester

Improved non-local electron thermal transport model for two-dimensional radiation hydrodynamics simulations

Energy Technology Data Exchange (ETDEWEB)

Cao, Duc; Moses, Gregory [University of Wisconsin—Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Delettrez, Jacques [Laboratory for Laser Energetics of the University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2015-08-15

An implicit, non-local thermal conduction algorithm based on the algorithm developed by Schurtz, Nicolai, and Busquet (SNB) [Schurtz et al., Phys. Plasmas 7, 4238 (2000)] for non-local electron transport is presented and has been implemented in the radiation-hydrodynamics code DRACO. To study the model's effect on DRACO's predictive capability, simulations of shot 60 303 from OMEGA are completed using the iSNB model, and the computed shock speed vs. time is compared to experiment. Temperature outputs from the iSNB model are compared with the non-local transport model of Goncharov et al. [Phys. Plasmas 13, 012702 (2006)]. Effects on adiabat are also examined in a polar drive surrogate simulation. Results show that the iSNB model is not only capable of flux-limitation but also preheat prediction while remaining numerically robust and sacrificing little computational speed. Additionally, the results provide strong incentive to further modify key parameters within the SNB theory, namely, the newly introduced non-local mean free path. This research was supported by the Laboratory for Laser Energetics of the University of Rochester.

Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

Science.gov (United States)

Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.;

An anisotropic diffusion approximation to thermal radiative transfer

International Nuclear Information System (INIS)

Johnson, Seth R.; Larsen, Edward W.

2011-01-01

This paper describes an anisotropic diffusion (AD) method that uses transport-calculated AD coefficients to efficiently and accurately solve the thermal radiative transfer (TRT) equations. By assuming weak gradients and angular moments in the radiation intensity, we derive an expression for the radiation energy density that depends on a non-local function of the opacity. This nonlocal function is the solution of a transport equation that can be solved with a single steady-state transport sweep once per time step, and the function's second angular moment is the anisotropic diffusion tensor. To demonstrate the AD method's efficacy, we model radiation flow down a channel in 'flatland' geometry. (author)

Structural, Bioinformatic, and In Vivo Analyses of Two Treponema pallidum Lipoproteins Reveal a Unique TRAP Transporter

Energy Technology Data Exchange (ETDEWEB)

Deka, Ranjit K.; Brautigam, Chad A.; Goldberg, Martin; Schuck, Peter; Tomchick, Diana R.; Norgard, Michael V. (NIH); (UTSMC)

2012-05-25

Treponema pallidum, the bacterial agent of syphilis, is predicted to encode one tripartite ATP-independent periplasmic transporter (TRAP-T). TRAP-Ts typically employ a periplasmic substrate-binding protein (SBP) to deliver the cognate ligand to the transmembrane symporter. Herein, we demonstrate that the genes encoding the putative TRAP-T components from T. pallidum, tp0957 (the SBP), and tp0958 (the symporter), are in an operon with an uncharacterized third gene, tp0956. We determined the crystal structure of recombinant Tp0956; the protein is trimeric and perforated by a pore. Part of Tp0956 forms an assembly similar to those of 'tetratricopeptide repeat' (TPR) motifs. The crystal structure of recombinant Tp0957 was also determined; like the SBPs of other TRAP-Ts, there are two lobes separated by a cleft. In these other SBPs, the cleft binds a negatively charged ligand. However, the cleft of Tp0957 has a strikingly hydrophobic chemical composition, indicating that its ligand may be substantially different and likely hydrophobic. Analytical ultracentrifugation of the recombinant versions of Tp0956 and Tp0957 established that these proteins associate avidly. This unprecedented interaction was confirmed for the native molecules using in vivo cross-linking experiments. Finally, bioinformatic analyses suggested that this transporter exemplifies a new subfamily of TPATs (TPR-protein-associated TRAP-Ts) that require the action of a TPR-containing accessory protein for the periplasmic transport of a potentially hydrophobic ligand(s).

Experience within international transport and direct rail services in meeting the IAEA requirement for a radiation protection programme(s)

International Nuclear Information System (INIS)

Billing, D.

2003-01-01

BNFL International Transport and Direct Rail Services have successfully developed appropriate Radiation Protection Programmes for their business. The business supports BNFL's worldwide Nuclear Fuel Services with key customer bases in Europe, Japan and the UK, utilising marine, rail and road modal transports. Experience in this business spans over 4 decades. The preparation of RPP's for each aspect of its operations has been made relatively straight forward in that the key elements within the internationally recognised model RPP (by WNTI) were already in place in BNFL's procedures to satisfy current National UK and International Regulations and supported by Management systems which comply with International Standards for Quality Assurance. (author)

Modelling of neutron and photon transport in iron and concrete radiation shieldings by the Monte Carlo method - Version 2

CERN Document Server

Žukauskaite, A; Plukiene, R; Plukis, A

2007-01-01

Particle accelerators and other high energy facilities produce penetrating ionizing radiation (neutrons and γ-rays) that must be shielded. The objective of this work was to model photon and neutron transport in various materials, usually used as shielding, such as concrete, iron or graphite. Monte Carlo method allows obtaining answers by simulating individual particles and recording some aspects of their average behavior. In this work several nuclear experiments were modeled: AVF 65 – γ-ray beams (1-10 MeV), HIMAC and ISIS-800 – high energy neutrons (20-800 MeV) transport in iron and concrete. The results were then compared with experimental data.

Radiation protection - Revision of French radiation protection regulations (1988)

International Nuclear Information System (INIS)

Mayoux, J.C.

1989-01-01

This article analyses the recent amendments to the 1966 and 1975 Decrees on general radiation protection principles and radiation protection of workers in large nuclear installations respectively and also describes national radiation protection law. In particular, the amendments incorporate the revised EURATOM basic radiation protection standards and the new international units (sievert and becquerel replace rem and curie) in the Decrees. (NEA) [fr

Activity transport in nuclear reactors

International Nuclear Information System (INIS)

Narasimhan, S.V.

2000-01-01

The chemistry of the primary coolant is such that the general material loss is immeasurably low. However, the generation of radioactive corrosion products in the coolant, their transportation and distribution to different out of core surfaces occur irrevocably through the life cycle of the reactor. This phenomena leading to the build up of radiation field, which is unique to the nuclear reactor systems, is the only major problem of any significance. Minimization of this phenomenon can be done by many ways. The processes involved in the mechanism of activity transport are quite complex and are not at all thoroughly understood. The codes that have been developed so far use many empirical coefficients for some of the rate processes, which are either partially justified by simulated experimental studies or supported theoretically. In a multi-metal system like that of the reactor, the corrosion rates or release rates need not be similar especially in reactors like PHWRs. The mechanisms involved in the formation of protective oxide coating are quite complex to model in a simplified manner. The paper brings out some these features involved in the activity transport modeling and analyses the need for extensive field related experimental work to substantiate the model. (author)

Impurity transport in the Wendelstein VII-A stellarator

International Nuclear Information System (INIS)

1985-01-01

Impurity radiation losses in net-current-free neutral-beam-heated plasmas in the Wendelstein W VII-A stellarator are the combined effect of particularly strong impurity sources and improved particle confinement as compared with ohmically heated tokamak-like plasma discharges. Experiments are described and conclusions are drawn about the impurity species, their origin and their transport behaviour. The impurity transport is modelled by a 1-D impurity transport and radiation code. The evolution of the total radiation in time and space deduced from soft-X-ray and bolometer measurements can be fairly well simulated by the code. Experimentally, oxygen was found to make the main contribution to the radiation losses. In the calculations, an influx of cold oxygen desorbed from the walls of the order of 10 13 -10 14 cm -2 .s -1 and a rate of fast injected oxygen corresponding to a 1% impurity content of the neutral beams in combination with neoclassical impurity transport leads to quantitative agreement between the simulation and the observed radiation. The transport of A1 trace impurities injected by the laser blow-off technique was experimentally studied by soft-X-ray measurements using a differential method allowing extraction of the time evolution of A1 XII, XIII radial profiles. These are compared with code predictions, together with additional spectroscopic measurements. The main features of the impurity transport are consistent with neoclassical predictions, which explain particularly the central impurity accumulation. Some details, however, seem to require additional 'anomalous' transport. Such an enhancement is correlated with distortions of the magnetic configuration around resonant magnetic surfaces. (author)

ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

OpenAIRE

Ali Payıdar AKGÜNGÖR; Abdulmuttalip DEMİREL

2004-01-01

Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properti...

Accuracy analysis of automodel solutions for Lévy flight-based transport: from resonance radiative transfer to a simple general model

Science.gov (United States)

Kukushkin, A. B.; Sdvizhenskii, P. A.

2017-12-01

The results of accuracy analysis of automodel solutions for Lévy flight-based transport on a uniform background are presented. These approximate solutions have been obtained for Green’s function of the following equations: the non-stationary Biberman-Holstein equation for three-dimensional (3D) radiative transfer in plasma and gases, for various (Doppler, Lorentz, Voigt and Holtsmark) spectral line shapes, and the 1D transport equation with a simple longtailed step-length probability distribution function with various power-law exponents. The results suggest the possibility of substantial extension of the developed method of automodel solution to other fields far beyond physics.

Accelerating execution of the integrated TIGER series Monte Carlo radiation transport codes

Science.gov (United States)

Smith, L. M.; Hochstedler, R. D.

1997-02-01

Execution of the integrated TIGER series (ITS) of coupled electron/photon Monte Carlo radiation transport codes has been accelerated by modifying the FORTRAN source code for more efficient computation. Each member code of ITS was benchmarked and profiled with a specific test case that directed the acceleration effort toward the most computationally intensive subroutines. Techniques for accelerating these subroutines included replacing linear search algorithms with binary versions, replacing the pseudo-random number generator, reducing program memory allocation, and proofing the input files for geometrical redundancies. All techniques produced identical or statistically similar results to the original code. Final benchmark timing of the accelerated code resulted in speed-up factors of 2.00 for TIGER (the one-dimensional slab geometry code), 1.74 for CYLTRAN (the two-dimensional cylindrical geometry code), and 1.90 for ACCEPT (the arbitrary three-dimensional geometry code).

Accelerating execution of the integrated TIGER series Monte Carlo radiation transport codes

International Nuclear Information System (INIS)

Smith, L.M.; Hochstedler, R.D.

1997-01-01

Execution of the integrated TIGER series (ITS) of coupled electron/photon Monte Carlo radiation transport codes has been accelerated by modifying the FORTRAN source code for more efficient computation. Each member code of ITS was benchmarked and profiled with a specific test case that directed the acceleration effort toward the most computationally intensive subroutines. Techniques for accelerating these subroutines included replacing linear search algorithms with binary versions, replacing the pseudo-random number generator, reducing program memory allocation, and proofing the input files for geometrical redundancies. All techniques produced identical or statistically similar results to the original code. Final benchmark timing of the accelerated code resulted in speed-up factors of 2.00 for TIGER (the one-dimensional slab geometry code), 1.74 for CYLTRAN (the two-dimensional cylindrical geometry code), and 1.90 for ACCEPT (the arbitrary three-dimensional geometry code)

Coupled heat transfer in high temperature transporting system with semitransparent/opaque material

International Nuclear Information System (INIS)

Du Shenghua; Xia Xinjin

2010-01-01

The heat transfer model of the aerodynamic heating coupled with radiative cooling was developed. The thermal protect system includes the higher heat flux region with high temperature semitransparent material, the heat transporting channel and the lower heat flux region with metal. The control volume method was combined with the Monte Carlo method to calculate the coupled heat transfer of the transporting system, and the thermal equilibrium equation for the transporting channel was solved simultaneously. The effect of the aeroheating flux radio, the area ratio of radiative surfaces, the convective heat transfer coefficient of the heat transporting channel on the radiative surface temperature and the fluid temperature in the heat transporting channel were analyzed. The effect of radiation and conduction in the semitransparent material was discussed. The result shows that to increase the convective heat transfer coefficient in heat flux channel can enhance the heat transporting ability of the system, but the main parameter to effect on the temperature of the heat transporting system is the area ratio of radiative surfaces. (authors)