摘要:

This paper presents a fuel cycle program for an intermediate power research reactor utilizing fully enriched MTR type fuel elements. The fuel cycle program is considered at equilibrium after many cycles have past.The program consists of shifting elements from positions of high importance outward to positions of low importance through several paths. The paths are staggered so that only the elements in one path are shifted at the conclusion of a cycle, and only one element is replaced. The method of calculating the fuel remaining in each element is shown utilizing a fractional burn-up factor for each position. Sample calculations are shown for the LPTR with 23 standard elements in the core and a desired burn-up of 15%.A method is proposed to obtain such an equilibrium condition starting with an initial loading of fuel elements having nearly equal fuel loading.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28053

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

The low energy total neutron cross section of Pu241has been measured from 0.02 ev to 2 kev using the Materials Testing Reactor (MTR) fast chopper. Curves of the total cross section are given and pronounced asymmetries are observed in several of the resonances below 12 ev. An estimate of the neutron strength function obtained from the average cross section in the kev energy region is (0.85±0.15)×10−4.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28054

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

The velocity dependent transport equation for a nonabsorbing semi-infinite medium with no sources is approximately solved by a variational method. A simple trial function, which takes into account the asymptotic behavior of the exact solution, is used to obtain an approximation for the extrapolation distanceq∞, and, by iteration, an approximation for the flux distribution.Numerical results are given for a monatomic gaseous medium with the atom mass equal to the neutron mass. The valueq∞= 0.9345l(∞) is obtained. The velocity distribution of the emerging neutrons shows a hardening effect, corresponding, in the average, to a 14% increase in the neutron temperature.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28055

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

Fundamental flux vectors have been obtained for the diffusion of bubbles in heated channels by considering bubble motion in a turbulent liquid as a Markoff process. These flux vectors lead to a nonlinear partial differential equation representing the void fraction, which has been linearized for the case of small void fractions and coupled to a similar partial differential equation governing heat flow into the liquid phase. The coupled differential equations are transformed into coupled integral equations which are solved to obtain axial void fraction and temperature distributions in a heated channel. The rate of vapor production at the wall and the rate constant for bubble growth have been calculated from experimental data on void fraction distributions at constant uniform flux. The model predicts the correct shape for the void fraction distribution curve as well as providing a plausible explanation of burnout phenomena in terms of the bubble slip velocity.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28056

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

The age of U235fission neutrons to indium resonance energy has been measured in a number of lattices of Th-H2O and Th-Al-H2O and compared with theoretical calculations. As a check on the procedure similar measurements were made in pure water yielding a result of 27.0±0.9 cm2. In addition, the ratio of the age of U233fission neutrons to the age of U235fission neutrons in water was found to be 0.948±0.033.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28057

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

Topological methods are used in the study of the effect of burnable fission products on power reactor kinetics. Taking as an example three different problems, it is shown that power is controlled when the amount of inserted reactivity is small: properties of stability in the large and of boundedness are found in the case of a short-lived absorbing fission product, burnable delayed neutron emitters, and the xenon-controlled reactor.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28058

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

Expressions are derived for the output, and time derivative of the output, of the simple diode pump circuit corresponding to an input pulse rate which is increasing exponentially with time. Solutions are obtained in numerical form for a series of values of the diode pump parameters. By a linear superposition of the outputs it is possible to predict the transient behavior of the multiple diode pump type of logarithmic rate meter and of the period signals derived from the output. The fluctuations or“noise”in the period meter output signal for random input pulses is also calculated for this type of rate meter. A comparison based on transient response and noise behavior shows the multiple diode pump circuit to be potentially superior to the simpler logarithmic diode type of rate meter.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28059

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

The complexities of the structure of dispersion fuels and of irradiation conditions makes interpretation of irradiation experiments difficult. A method is suggested for consideration of irradiation conditions independently of material variables so long as these variables are held constant. Estimates are made of the relative severity of experiments made on identical specimens under different experimental conditions.A numerical application of the analysis was made to specimens of 18-8 stainless steel with 25 and 30 w/o UO2. Approximate failure limits for both specimen compositions are obtained although both sets of data are very limited. Further experimentation is needed to more fully establish the limits of the application of the proposed model.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28060

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

A crosscorrelation method for the study of the small signal response of nuclear reactor systems is presented. The technique and equipment necessary for the implementation of the method are discussed. Results from experiments performed on the Godiva and Kiwi-A3 reactors are reported.Experiments have shown that the method and the technique give very satisfactory results under adverse experimental conditions.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28061

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

A calculational and experimental procedure is developed to eliminate nearly all of the uncertainties in the source and foil corrections required in most age experiments. The calculations are rigorous and yield, in addition to flux ages, values of actual foil activation at the exact spatial positions of the measurements; comparisons with experiment therefore involve fewer assumptions and produce more information. Being required in the calculations, the angular sensitivity of Cd-covered In foils is determined theoretically and checked with measurements. Comparisons between new calculations and data from old activation experiments with fission and Na-Be sources in water are made; the results suggest that a new type of fission source experiment is still called for.

ISSN:0029-5639    

DOI:10.13182/NSE61-A28062

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor