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Volume 30, Issue 1
Displaying 1-8 of 8 articles from this issue
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Motoyasu KINOSHITA1993 Volume 30 Issue 1 Pages 1-17
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSthis paper is to cover brief history of the development of LWR fuel performance analysis codes in Japan. This includes the FEMAXI-III code which calculates local stress and strain of the cladding at power ramp due to the pellet cladding mechanical interaction (PCMI) using axisymmetric finite element method. From this code some improved codes were developed, such as FEMAXI-IV, IRON and EIMUS. The FEMAXI-IV is developed by JAERI to add capacity of transient analysis and the IRON code was developed by Shikoku Electric Power Co. to analyze fuel reliability at load following operation and the EIMUS code was developed by CRIEPI for high burnup analysis. The major objective and contents of adapted submodels in these codes are presented with some calculational results. The future development and utilization of the codes, especially for performance analyses at high burnup, will be briefly discussed.View full abstractDownload PDF (1269K) -
Yasuyuki NAKAO, Takuro HONDA, Masaki FUJITA, Kazuhiko KUDO, Hideki NAK ...1993 Volume 30 Issue 1 Pages 18-30
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA method for calculating the neutron heating rate in plasma systems at densities and temperatures of interest for inertial confinement fusion is presented. The basic equations consist of the transport equations for neutrons and their recoil ions, being written in terms of the modified Eulerian coordinates originally proposed by Wienke (1974). After presenting the calculational model, numerical results are given for a particular test problem, i.e. the deposition of 14-MeV source neutron energy in expanding D-T spheres. It is shown that the energy transport by recoil ions has a considerable influence on the neutron heating. Calculations neglecting recoil-ion transport fail to account for the temperature dependence of neutron heating and overestimate the deposition to plasma ions.View full abstractDownload PDF (871K) -
Keisuke KOBAYASHI, Hirohiko KIKUCHI, Ken TSUTSUGUCHI1993 Volume 30 Issue 1 Pages 31-47
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSA neutron multigroup transport equation in x-y-z geometry is solved by the spherical harmonics method using finite Fourier transformation. Using the first term of the Fourier series for the space variables of spherical harmonics moments, three-point finite difference like equations are derived for x-, y- and z-axis directions, which are more consistent and accurate than those derived using the usual finite difference approximation, and these equations are solved by the iteration method in each axis direction alternatively. A method to find an optimum acceleration factor for this inner iteration is described. It is shown in the numerical examples that the present method gives higher accuracy with less mesh points that the usual finite difference method.View full abstractDownload PDF (1027K) -
Makoto UEDA, Shigeto KIKUCHI, Tsukasa KIKUCHI, Hironori KUMANOMIDO, Ta ...1993 Volume 30 Issue 1 Pages 48-59
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe neutron emission-rate (NER) method for burnup measurement of a spent LWR fuel bundle submerged in water has been studied by focusing on the spatial higher harmonics effects inevitable for the application of a formula based on the one-point reactor model.
Verification studies of this method have been made through calculations and simulation experiments using the fresh UO2 fuel-rod bundles of nxn arrays (3 ?? n ?? 23, 0.22 ?? keff ?? 0.94), and its applicability has been shown for the spent fuel bundle. As a practical example, an actual formula has been given for a spent PWR fuel bundle of 14x14 array of 3.5 wt% initial enrichment and cooling time of 1, 000 days.View full abstractDownload PDF (904K) -
Hiroyuki TAKAHASHI, Masaharu NAKAZAWA1993 Volume 30 Issue 1 Pages 60-67
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSRecently a remarkable progress has been made in fast ADCs such as flash ADCs. This paper shows a method of applying these fast ADCs to the radiation measurements. Direct sampling and digitizing of output signal from preamplifier were examined using the weighted sum of sampled data in order to obtain the energy of incident radiations. As a result, this method is applied to γ-ray spectroscopy by a Nal(Tl) scintillation counter to give sufficient performance. Because the present method treats the signal waveform itself, the standard waveform of input signals can be measured. After the standard waveform was obtained by preliminary measurement, a trial was made to select the similar waveforms to the standard waveform using the resembrance factor. With this selection, improvement of energy resolution was observed in the measurement of 60Co γ-ray.View full abstractDownload PDF (529K) -
Takayoshi ISEKI, Mitsuharu TEZUKA, Chang-Sam KIM, Tetsuya SUZUKI, Hisa ...1993 Volume 30 Issue 1 Pages 68-77
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSPressureless-sintered AlN and hot-pressed, pressureless-sintered and reaction-bonded SiC were neutron irradiated at temperatures between 100 and 785°C up to a fluence of 5.2X1034 n/m2. The hardness was increased by up to 51% in AlN and 84% in SiC, The hardness decreased after annealing at temperatures around the irradiation temperature. At the same temperatures, the macroscopic length, which was increased by irradiation, also began to decrease. The hardness and length were almost recovered after 1, 2001, 400°C annealing. Thus, hardening in irradiated AlN and SiC is controlled by the number of point defects, or, more precisely, by the strain caused by small point defect clusters which pin down dislocation movement. Dislocation loops were still observed in some samples after 1, 400°C annealing while the hardness was almost recovered to that in the unirradiated state. Thus, the existence of dislocation loops is not grounds for hardening in irradiated AlN and SiC.View full abstractDownload PDF (5866K) -
Yoshitake SHIRATORI, Toshiyuki FURUBAYASHI, Mitsuo MATSUMOTO1993 Volume 30 Issue 1 Pages 78-88
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSFugen has been operating safely and smoothly for 13 yr using mainly plutonium-uranium mixed oxide (MOX) fuels, and much operation data has been accumulated during this time. Fugen's core management has been established, and its core characteristics have been evaluated through the operation.
The effect of 241Am accumulation and plutonium composition on the reactivity must be considered when many MOX fuels are used in a thermal reactor. Calculation accuracy of core analysis code is good and core characteristics are well evaluated when the consideration is made of the above effect.
Fuel inspection shows that there is no big difference between MOX and UO2 fuel peformance.View full abstractDownload PDF (714K) -
Shigeo HATAMIYA, Tomoya MUROTA, Osamu YOKOMIZO1993 Volume 30 Issue 1 Pages 89-90
Published: January 25, 1993
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSDownload PDF (162K)
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