摘要:

AbstractThe kinetics of a flux-trap cylindrical reactor system were studied both theoretically and experimentally. A state-variable approach was used to develop a twenty-fourth-order model describing neutron and temperature kinetics in 14 regional system components. The modified Mikhailov method was used to determine the stability of the model. The reactor system was studied using step testing and pseudorandom multifrequency binary sequence testing procedures with a small-computer based instrumentation system. Measurements were made at powers of 1, 2.5, and 4 MW. The frequency response analysis of the system model compared favorably with experimental observations.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27338

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

AbstractThe emission probabilities of delayed neutrons are reevaluated on the basis of recently determined fission yields. The accuracy of the probabilities for thermal and fast fission of233U and235U is examined by summation of the individual delayed-neutron yields of the precursors and by comparison with the unseparated group and directly measured total delayed-neutron yields.The good agreement of the results obtained by the two independent methods indicates that the derived probabilities are accurate enough for the calculation of delayed-neutr on yields for other fissioning systems and for reactor calculations.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27339

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

AbstractFor several proposed fusion-reactor-blanket designs, the changes in the tritium breeding ratios due to estimated errors in nuclear cross-section data are presented and compared. The designs considered are those proposed at the Oak Ridge National Laboratory, the reference theta-pinch reactor design proposed at the Los Alamos Scientific Laboratory, and the reference fusion power plant design proposed at the Princeton Plasma Physics Laboratory. Results are presented for the changes in the breeding ratios due to estimated energy-dependent errors in various partial cross sections of6Li,7Li, C, Be, and F. The7Li(n,n’)α,t cross section, the Be(n,2n’) cross section, and the fluorine cross sections are found to introduce changes of the order of a few percent in the breeding ratios for the various designs. Sensitivity profiles that show the changes in the breeding ratios due to changes in these cross sections in specific energy ranges are presented.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27340

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

AbstractCalculations and resulting data are described which are intended for use in estimating the protection afforded by buildings against nuclear radiations emitted from a nuclear burst in the first half minute or so. The basic source configuration is that for which one assumes equal likelihood of the explosion occurring on a ring of elevation 30 deg above the horizontal, relative to a structure location on the ring axis. Source spectra and angular distributions corresponding to large distance (≳1 mile) from burst point to structure are used. As sources we discuss here only gamma rays from fission products and from neutron interactions with air molecules.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27341

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

AbstractThe possibility of electromagnetic self-excitation of the fluid flow in liquidmetal fast breeder reactors has been predicted based on gross dimensions without consideration of the details of the flow. In the present paper the flow in the reactor core cooling ducts is analyzed, and it is shown that self-excitation is not expected. Simplified field and flow patterns are assumed since the results of both experiments and the usual analytical techniques are not expected to be of practical value.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27342

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

AbstractComputer programs such as COBRA IIIC, which handle flow blockages, use a transverse momentum balance on a control volume of uniform width connecting any two subchannels to evaluate cross flow and momentum exchange effects on axial flow distribution. The transverse momentum balance employed has several constants that need to be determined empirically. This Note describes the method to develop such a correlation for three blockage configurations. It was found that with a constant width control volume, the data could not be satisfactorily correlated. A variable width control volume was therefore used to correlate the data behind flow blockage. A similar correlation could be developed ahead of the blockage but is not completed yet. Although the applicability of the correlation is limited to the blockage configurations analyzed, the variable width control volume method of correlating data that has evolved from this study is of general use in correlating such data.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27343

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

摘要:

AbstractAn analysis of the hydraulic entry-length problem in concentric annuli has been made by the linearized finite-difference method and the results are reported in this Note. Fifteen annuli of radii varying in ratio between 0.05 and 0.955 were investigated and typical radial velocity profiles at various axial distances from the annulus entrance are presented. A means for determining the pressure drop in the entry region is included. In the course of the study the developing axial profiles were observed to be in agreement with results in the literature.

ISSN:0029-5639    

DOI:10.13182/NSE75-A27344

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE75-A27345

出版商:Taylor&Francis    

年代:1975

数据来源: Taylor