摘要:

AbstractThe Monte Carlo method can be used to compute the gamma-ray backscattering albedo. This method was used by Raso to compute the angular differential albedo. Raso’s results have been used by Chilton and Huddelston to adjust their well-known albedo formula.Here, an efficient estimator is proposed to compute the double-differential angular and energetic albedo from gamma-ray histories simulated in matter by the three-dimensional Monte Carlo transport code TRIPOLI. A detailed physical albedo analysis could be done in this way.The double-differential angular and energetic gamma-ray albedo is calculated for iron material for initial gamma-ray energies of 8, 3, 1, and 0.5 MeV.

ISSN:0029-5639    

DOI:10.13182/NSE94-A21499

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

AbstractMonte Carlo program is described that calculates Dancoff factors in arbitrary arrangements of cylindrical or spherical fuel elements. The fuel elements can have different diameters and material compositions, and they are allowed to be black or partially transparent. Calculation of the Dancoff factor is based on its collision probability definition. The Monte Carlo approach is recommended because it is equally applicable in simple and in complicated geometries. It is shown that some of the commonly used algorithms are inaccurate even in infinite regular lattices. An example of application includes the Canada deuterium uranium (CANDU) 37-pin fuel bundle, which requires different Dancoff factors for the symmetrically different fuel pin positions.

ISSN:0029-5639    

DOI:10.13182/NSE94-A21500

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

AbstractTime-dependent sensitivity techniques, which have been used in the past for standard reactor applications, are adapted to calculate the impact of data uncertainties and to estimate target data accuracies in radiotoxicity evaluations. The methodology is applied to different strategies of radioactive waste management connected with the European Fast Reactor and the Integral Fast Reactor fuel cycles. Results are provided in terms of sensitivity coefficients of basic data (cross sections and decay constants), uncertainties of global radiotoxicity at different times of storing after discharge, and target data accuracies needed to satisfy maximum uncertainty limits.

ISSN:0029-5639    

DOI:10.13182/NSE94-A21501

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

AbstractTotal attenuation cross sections for several sugars are measured for 661.6-, 1173-, and 1332.5-keV photons in a narrow beam geometry setup, by using a hyperpure germanium detector. These values are compared with the values calculated by using the mixture rule based on Hubbell’s data for the individual elements and are found to be in good agreement. Based on the measured values for different sugars, a set of mean mass attenuation coefficients for sugars is given for the energies of interest.

ISSN:0029-5639    

DOI:10.13182/NSE94-A21502

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

AbstractAnalyses were performed by using the U. S. advanced liquid metal reactor (ALMR) core design to determine the feasibility of using it as a99Tc burner while reducing the sodium void reactivity effect (SVRE). A layer of99Tc of variable thickness was inserted around the core midplane in rows 2 through 5, and all blanket assemblies were replaced with fuel assemblies. The results indicate that a core with a 34-cm-thick layer in rows 2 through 5 has the optimum characteristics of SVRE,99Tc destruction rate, and fuel enrichment.

ISSN:0029-5639    

DOI:10.13182/NSE94-A21503

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor