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Volume 4, Issue 1
Displaying 1-9 of 9 articles from this issue
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Extraction behavior of neptunium icns in HCl-TBP systemHassan M. SAMMOUR1962 Volume 4 Issue 1 Pages 2-8
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSUsing 239Np-tracer, the extraction behavior of neptunium ions has been studied in the tri-n-butyl phosphate-hydrochloric acid system by the discontinuous countercurrent technique. The results indicate that 5.4N HCl is the most suitable acidity to effect a good simultaneous separation fo the three stable oxidation species in solution. Neptunium (VI), the most extractable species, was only extracted in the organic phase, Np (V) being less extractable remained in the last 10 fractions of the aqueous phase and Np (IV) was concentrated in the first fourty aqueous portions of the extractor. The separation permitted calculation of the amount of each oxidation species in the original mixture. The effect of disproportionation of Np (V), reduction of the original mixture with zinc or oxidation with KClO3, on the extraction behavior has bean examined and the results were explained in the light of the known views.View full abstractDownload PDF (464K) -
General studyKeichi OSHIMA1962 Volume 4 Issue 1 Pages 8-16
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSA systematic study of the basic chemistry of solvent extraction of metals by organophosphorus compounds carried out in JAERI is reported. As for the general study, thermodynamic and structural chemical approaches were employed.
The thermodynamical treatment of the distribution equilibrium measurement was carried out rather precisely to analyse the mechanism of solvent extraction. This was applied to determine the compositions of the complexes formed and the chemical reactions underlying.
Further, it was shown the competition of metal and proton acid could clearly explain the extraction behaviors in these systems.
The spectroscopic measurements of the solvents were conducted. Especially, in the infra-red region, the shift of the P=0 vibrational spectra of the solvent and the splitting of the NO3 vibrational spectra of the nitrate ions gave very powerful measures to study the microscopic mechanism of complex formation between the solvent and the species extracted.
The thermodynamic and structural chemical approaches carried out were turned out to be in good accord and complementary.View full abstractDownload PDF (571K) -
Tomitaro ISHIMORI, Takeo FUJINO1962 Volume 4 Issue 1 Pages 16-24
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSThe isotopic ratio of 235U/238U is determined according to the technique of neutron activation analysis without any tedious chemical separation. Although several works had been carried out along this line, the irradiation of uranium sample was limited to some particular conditions because of high fission cross section value for 235U.
In the present methods, 100 mg of uranium oxide-oxalic acid mixture (1: 8000) is irradiated in JRR-1 for 1 hr. After about one day cooling, the γ-activity of the sample is studied spectrometrically.
The dilution of uranium sample with a large amount of oxalic acid gives various advantages in slowing down fast neutrons, in capturing recoil fission products or in taking very small amount of uranium for irradiation.
Two methods are proposed and compared each other. The first method is based on the relative ratio between activities in the energy region containing γ-activity due to 239Np and those in the higher energy region free from the activity of 239Np. In the second method, the strength of γ-activity due to fission produtcts is measured as the amount related closely to the 235U concentration.View full abstractDownload PDF (2112K) -
Kenji ISHIMATSU1962 Volume 4 Issue 1 Pages 24-30
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSA response matrix which converts scintillation pulse height spectra to incident photon spectra is presented here
It is applicable for broad parallel γ-rays up to 1.5 MeV incident to a 2 in. long by 2 in. diameter sodium-iodide crystal. Its energy channel is wide as 0.1 MeV. Reliability of the matrix is estimated by experimental pulse height spectra from a 137Cs source. The resultant error in a energy channel is estimated as large as 5 % of number of incident photons which have energies higher than the energy of the channel.
A correction to incident γ-rays of uniform angular distribution is also discussed.View full abstractDownload PDF (485K) -
Masayoshi KANNO, Sanya KOKUBO1962 Volume 4 Issue 1 Pages 30-36
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSInterest in various pyrometallurgical processes of irradiated nuclear fuels has grown because they may serve as an aid to reduce fuel processing costs through the possibility of handling short-cooled fuels as well as the elimination of chemical conversions. As one of these pyrometallurgical processes, the fractional crystallization from low melting solvent metals using liquid zinc was investigated in this paper.
The process involves the dissolution of an irradiated material in zinc with some flux and subsequent separation through crystallization and precipitation of intermetallic compounds (U2Zn17). The required reduction in solubility was accomplished by temperature change from 750°C to 550°C.
Specimens used were artificial fissium alloys containing zirconium made by vacuum resistant-heat melting and injection casting.
The results of metallography and chemical analysis of slow cooled zinc ingots containing 3% uranium, showed the availability of the separation between solvent zinc and precipitated U2Zn17 phase by decantation. Thus separated cake whith mainly consisted of U2Zn17 containing from 6 % to 16 % uranium and the purified uranium sponges were recovered by vacuum distillation of these separated cakes at temperature 1000°C. The decontamination factors for zirconium obtained were 2.29.5. These decontamination factor were theoretically and experimentally confirmed to depend upon the uranium content in the separated cake.View full abstractDownload PDF (6945K) -
Taiji KURIHARA, Hisao KIMURA, Yutaka YAMAMOTO, Takehiko ISHIHARA, Tets ...1962 Volume 4 Issue 1 Pages 37-44
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSThe inclined pipe type extractor, newly proposed, is applicable to liquid-liquid extraction processes of petroleum refining, petro-chemical and other chemical industries, especially to nuclear fuel reprocessing very economically with high efficiency.
In this work, in order to evaluate the use of the inclined pipe type extractor on uranium extration, the flooding point, hold up of each phase, and extraction efficiency were studied for the system, water-uranylnitrate-30% T. B. P. kerosene solution. For the experiments, spiral shaped, inclined pipe type extractors of acryl resin were used, the pipe diameters being 21.6 and 35.7 mm.
From the results of these investigations, it is shown that the inclined pipe type extractor has special advantages which other extraction equipment heretofore has never had. That is to say, the flow capacity of this type extractor is several times larger than that of a pulse column or another type extractor, and it is possible to adapt the height of this extractor in a comparatively wide range, by adjusting the pipe diameter and other factors.View full abstractDownload PDF (4561K) -
Ryokichi TANAKA1962 Volume 4 Issue 1 Pages 45-51
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSThe reactor kinetics with the surface deformation of an outer reflector was solved by a perturbation method.
Although the spacial reactor kinetics has been discussed by many authors on the different standpoints, we can not apply them directly for our present purpose. Here, a diffusion equation was transformed into an integral equation to obtain the time components of the neutron flux corresponding to surface deformations. As compared with the ordinary perturbation such as the insertion of a poison, in which the outer boundary of the reactor is fixed, we have to treat the extra terms besides the main source term of a surface integral. As examples, five cases of surface deformations were treated and the corresponding neutron flux responses were derived for the one-dimensional slab reactor.
The method studied here is applicable directly to a multigroup diffusion model.View full abstractDownload PDF (414K) -
Yuzo FUKAI1962 Volume 4 Issue 1 Pages 52-64
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSThe present status of reactor theory is considered from viewpoints of reactor design and is presented. It is always necessary for reactor designer to compile the newest know-how of calculating technique for reactor analysis in order to reduce design cost. Then, we present a short note for the lastest papers about reactor physics which are appeared in journal and so on, and discuss many unknown factors which should be solved. In Chap. 1, suggestions for reducing the calculation cost are considered. In Chap. 2, many fundamental problems are given; i. e. evaluation of cross section value, solutions of Boltzmann transport equation, neutron slowing down and criticality problems. Review of the lastest calculating methods for criticality calculation is described in Chap. 3. Recent problems about neutron resonance, thermalization and breeding are given in Chaps. 4, 5 and 6, respectively. However, we can not present only short information about time dependent problems because we do not have enough space in our paper to describe them in detail.View full abstractDownload PDF (1101K) -
1962 Volume 4 Issue 1 Pages 65-67
Published: January 30, 1962
Released on J-STAGE: March 31, 2009
JOURNAL FREE ACCESSDownload PDF (4054K)
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