摘要:

AbstractAn investigation is conducted regarding the equivalent-cell assumption, used in reactor calculations. We calculate the thermal utilization using the real cell shape and allowing absorption in the moderator. The results show that for heavy water and graphite lattices, the correction due to the equivalent-cylindrical-cell assumption is of the same order of magnitude as the correction due to the neglect of absorption in the moderator.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26036

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractAn analytical approach is developed to permit determination of gamma radiation attenuation as it passes through two-legged rectangular ducts and shelter entranceways. The approach used employs the albedo concept for wall scattering and includes correction terms necessary to account for the“corner lip effects.”With appropriate simplifying assumptions, moderately simple engineering formulas are obtained. Actual use of the formulas requires better knowledge of differential angular albedo than is presently available; however, by assuming isotropic distribution of the albedo function, a very good comparison of experimental information with results calculated by this technique is obtained.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26037

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractThe total and activation cross sections of Dy164have been measured in the energy range 0.02 to 2.0 ev. The cross sections, which are not 1/υabove 0.1 ev, are well represented by the single level Breit-Wigner formula for a bound level with parametersE0=−1.89±0.04 ev;Γn0= 0.041±0.001 ev;Γ= 0.166±0.004 ev; andσ0Γ2= 4280±100 barns ev.2

ISSN:0029-5639    

DOI:10.13182/NSE61-A26038

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractFUELCYC is a code, written in the Fortran II language for a 32,000-word IBM 704 computer, which has been developed for the study of fuel cycles in large cylindrical thermal power reactors. It is a two-dimensional diffusion-theory code in which it is assumed that the reactor core is symmetrical in the azimuthal direction. Core properties such as the fuel composition, burnup, flux and power-density distributions, and reactivity can be calculated throughout the life history of the fuel for different methods of managing fuel and control poisons. Only a few minutes of computer time are required for a complete fuel-cycle analysis of the life history of the core.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26039

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractExamples are given of the application of computer code FUELCYC to fuel cycle analysis of pressurized water, organic moderated, and heavy water reactors. Properties of these reactors evaluated include the flux energy spectrum, changes in fuel composition and effective cross sections on irradiation, and changes in power density distribution. The effects of different initial fuel enrichments and six different fuel and poison management procedures on the average burnup of fuel, its maximum burnup, the peak-to-average power density ratio and fuel cycle costs are investigated. Fuel cycle costs may be reduced by having good neutron economy, high burnup, and a steady fueling procedure in which neutrons are not wasted in control poison. Of the fueling methods examined, out-in fueling, or some discontinuous approximation to it, seems best because of its flat power-density distribution and relatively low fuel cycle cost. Where mechanically feasible, bidirectional axial fueling is also advantageous because of the uniform fuel burnup it makes possible and its low fuel cycle cost.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26040

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractUsing a large liquid scintillator as the fission neutron detector the number of prompt neutrons per fission,ν, for Th232and U238have been measured at neutron energies of 3.6 and 14.9 Mev. The values for U238of 2.79±0.09 and 4.75±0.12 are in good agreement with earlier accurate measurements while the Th232values of 2.42±0.10 and 4.43±0.13 agree with the results of Kuzminovet al.and of Leroy but not so well with that of Smithet al.The parameters of the equation(En) =(0) +a·En, whereEnis the neutron energy in Mev, have been obtained by fitting a straight line to the available data using the least mean square method yielding(En) = 1.87 + 0.177Enfor Th232and(En) = 2.30 + 0.154 Enfor U238.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26041

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractReactor period-reactivity relations and open-loop transfer functions may be determined directly by numerical integration of“rod-drop”neutron decay data without analysis into delayed neutron period and abundance values. Period-reactivity relations obtained by this method for two critical assemblies with and without beryllium in the core and reflector are compared with corresponding results calculated from the“in-hour”equation. Results of the application of the rod-drop experiment to the determination of the open-loop reactor transfer function are given for the beryllium-moderated assembly.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26042

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractThe general procedure of solving the one-velocity Boltzmann equation in the case of plane geometry is presented. It is assumed that the scattering function can be expanded into the finite series of Legendre polynomials. The complete set of eigenfunctions of the Boltzmann equation is found. The orthogonality and completeness of the eigenfunctions are proved. By way of illustration, solutions of some basic problems of neutron diffusion are given.

ISSN:0029-5639    

DOI:10.13182/NSE61-1

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractThe stability and instability properties of homogeneous nuclear reactors with a single temperature coefficient of reactivity which is temperature dependent are studied by means of Liapounoff's Second Method. The special case of a temperature coefficient linearly dependent on temperature is solved completely for a space-independent model and it is shown that all solutions are bounded and tend asymptotically to a constant if the reactivity decreases as the temperature approaches large values. In some conditions, the reactor has two stable equilibrium points (bistable).

ISSN:0029-5639    

DOI:10.13182/NSE61-A26044

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractTantalum-sheathed plutonium fuel pins have been prepared for the first core loading of the Los Alamos Molten Plutonium Reactor Experiment-I. Twenty-five kilograms of plutonium–10 atomic per cent iron alloy were prepared by co-reduction and by co-melting methods. After casting the alloy into rods, each rod was machined and finished to a 0.357 in. diam piece weighing 175 gm. The finished alloy rod was finally placed in a tantalum sheath which was then sealed by fusion welding to a tantalum cap. Procedures and equipment used for alloying, casting, machining, welding, and inspection are described and illustrated by photograph. Methods used to prepare rods of other low melting plutonium alloys are also discussed.

ISSN:0029-5639    

DOI:10.13182/NSE61-A26045

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor