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Tsuchiya, Harufumi; Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Umemoto, Daigo*; Makishima, Kazuo*; GROWTH Collaboration*
Proceedings of Science (Internet), 358, p.1163_1 - 1163_6, 2021/07
Oi, Motoki
Shiki, 43, P. 3, 2019/06
At the J-PARC Materials and Life Science Facility (MLF), we developed an Au-In-Cd alloy as a low activation neutron absorber for reducing the activity of moderator assembly, and put it to practical use in the reflector and moderator. As a method to confirm the distribution of indium in the alloy, pulse neutron imaging method is adopted, and the individual element distribution is measured by focusing on the resonance peak of indium, and the uniformity of the alloy is confirmed.
Takada, Hiroshi
Kasokuki Handobukku, p.330 - 333, 2018/04
Spallation neutron source provides thermal and cold neutrons for materials researches. Those neutrons are obtained by slowing down the neutrons generated in a neutron production target by injecting high energy protons in surrounding reflector and moderators. This article introduces basic characteristics of the neutron production target at first, and then explains the characteristics of moderator, especially the design to generate high intensity and high quality neutron pulses with narrow width in the moderators used in the 1-MW spallation neutron source at J-PARC. Furthermore, the design procedure of the spallation neutron source is described.
Yamamoto, Toshihiro; Miyoshi, Yoshinori
Nuclear Science and Engineering, 142(3), p.305 - 314, 2002/11
Times Cited Count：2 Percentile：16.96(Nuclear Science & Technology)Mechanisms of a positive temperature reactivity coefficient that occurs in a dilute plutonium solution are investigated based on the perturbation theory and the four-factor formula. The temperature coefficient of a solution fuel is positive if the adjoint flux or 
f between 0.05eV and 0.2eV increases with neutron energy. As compared to Pu-239, Pu-241 has a tendency to make the temperature coefficient of a plutonium solution. As Pu-241 in a plutonium solution decays into Am-241 with time, the temperature coefficient becomes more positive. Since the capture cross sections of most neutron absorbers such as boron and gadolinium decreases with increasing neutron energy, soluble absorbers make the temperature coefficient positive for higher concentration plutonium solution. Cadmium and samarium solved in a dilute plutonium solution exceptionally can keep the temperature coefficient. A fixed neutron absorber generally makes the temperature coefficient negative regardless of the property of absorber materials.
-ray absorbed doses under criticality accident conditions at TRACY using tissue-equivalent dosimetersSono, Hiroki; Yanagisawa, Hiroshi; Ono, Akio; Kojima, Takuji; Soramasu, Noboru*
Nuclear Science and Engineering, 139(2), p.209 - 220, 2001/10
Times Cited Count：7 Percentile：48.66(Nuclear Science & Technology)no abstracts in English
Onodera, Seiji; Hirose, Hideyuki; Izawa, Kazuhiko; Tanino, Shuichi; Kaminaga, Jota*; Sakuraba, Koichi; Miyauchi, Masakatsu; Tonoike, Kotaro; Miyoshi, Yoshinori; Yanagisawa, Hiroshi; et al.
JAERI-Tech 2001-057, 54 Pages, 2001/09
JAERI-Tech-2001-057.pdf:4.28MB
no abstracts in English
-ray spectroscopic methodsFurutaka, Kazuyoshi
JNC TN8400 2000-028, 70 Pages, 2000/10
JNC-TN8400-2000-028.pdf:1.71MB
This report describes the study done by the author as a postdoctoral research associate at Japan Nuclear Cycle Development Institute. This report is divided into two parts: improvements in accuracy in determination of thermal neutron capture cross sections, and improvements in accuracy of photo-nuclear absorption cross section measurements using the HHS. (1)In the measurements of thermal neutron capture cross sections using an activation method, accuracies of the final results attained are limited by (1) accuracy of -ray peak detection efficiencies, and (2) accuracies of -ray emission probabilities. In this study; to determine thermal neutron capture cross sections more accurately, the following researches have been done using a newly developed three-dimensional coincidence measurement system: (1)accurate determination of -ray standard sources using a - coincidence method, for precise calibration of -ray peak detection efficiency, and (2) development of a 
- coincidence measurement system using a plastic scintillation detector as a -ray detector, for the determination of -ray emission probabilities of short-lived nuclides, and measurement of -ray emission probabilities of 
Tc nuclide using the coincidence system. (2)To transform radioactive nuclides with small thermal neutron capture cross sections, use of photonuclear absorption reaction has been suggested. In order to transform these nuclides efficiently using the reaction, one has to know detailed behavior of the photo-absorption cross sections. In this study, a Monte-Carlo simulation code has been used to create a standard set of -ray response functions of the high-resolution high-energy spectrometer (HHS), to enable reliable analyses of the data obtained by the spectrometer.
Wada, Hiroaki
JNC TN8400 2000-015, 37 Pages, 2000/03
This report describes the study done within the period of time when I was postdoctoral research worker at Japan Nuclear Cycle Development Institute. The report includes two parts as follows. (1) Exact Solution of Electric Transitions for High Energy photons. Technologies for creating high-energy beams have been rapidly developed. These advancements make the research using high-energy -rays more important. The electric transition rates for high-energy -rays were formulated. The electric multipole fields were treated strictly in the process of calculating the electric transition rates and the nuclear states were taken as the harmonic oscillator wave functions. (2) Production of the isomeric state of 
Cs in the thermal neutron capture reaction 
Cs(n, )Cs. In order to obtain precise data of the neutron capture cross section of the reaction Cs(n, )Cs, the production probability of isomer state 
Cs was measured in this work. The 1436 keV -ray emitted from both of 
Cs and Cs was measured. A production ratio of Cs to (Cs and Cs) was deduced from time dependence of peak counts of 1436keV -ray. The probability of the production of CS was obtained as 0.75
0.18 and this value revised the effective cross section upwards 92%. The effective cross section 
and the thermal neutron capture cross section 
were obtained as =0.290.02 b and =0.270.03 b with taking into account the production of 
Cs.
Haruyama, Mitsuo
Genshiryoku eye, 45(11), p.77 - 79, 1999/11
no abstracts in English
Cs(n,)
Cs; Fundamental data for the transmutation of nuclear wasteHatsukawa, Yuichi; Shinohara, Nobuo; ; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu; *; *; Harada, Hideo*
Journal of Radioanalytical and Nuclear Chemistry, 239(3), p.455 - 458, 1999/00
Times Cited Count：2 Percentile：75(Chemistry, Analytical)no abstracts in English
Maruyama, Tadashi; ; ; Onose, Shoji;
PNC TN9410 97-077, 177 Pages, 1997/07
Postirradiation examinations of JOYO MK-II control rods have been carried out since 1983, where 16 subassemblies with total 110 absorber pins of initial load to the fifth reload control rods have been subjected to a number of both non-destructive and destructive examinations. In the course of postirradiation examinations, a cracking of cladding tube was found in the total 15 absorber pins in five control assemblies. This paper indicates the results of postirradiation examinations and analysis of absorber pin performance using CORAL code to elucidate the cause of absorber pin cracking in JOYO MK-II control rods. No crack was found in absorber pins whose maximum burnup was lower than 39 
10
cap/m
, whereas all the cracked pins had burnup of higher than 43 10 cap/m with the initial gap between B
C pellet and cladding larger than 0.44 mm. The cracks were found at around positions corresponding to the lowest BC pellet in the stack. The ceramography analysis indicated that BC pellet exhibited extensive cracking and a part of gap between pellet and cladding closed. The cladding deformation had an ovality and the cracks tended to occur at the shorter diameter side. The cracked surface of absorber pin was of a typical grain boundary fracture. The result of He analysis for the cladding material indicated a substantial amount of He accumulation at the inner surface of cladding, but the bulk He content was not anomalously high compared with those in the neutron irradiated stainless steels. TEM observation indicated He bubbles was not clearly found in the as-irradiated cladding material. The cause of cladding failure was attributed to the ACMI where the gap closure due to relocation of BC pellet took place from early times of irradiation. The code analysis by CORAL indicated that the cladding strain due to ACMI was not fully absorbed by the irradiation creep and that the plastic strain became large enough to ...
Miyakawa, Shunichi; ; Soga, Tomonori
PNC TN9410 97-068, 113 Pages, 1997/07
Since the first control rod design for the Joyo Mk-II core (about twenty years ago), there have been several challenging improvements; for example, a helium venting mechanism and a flow induced vibration prevention mechanism. Forty-four control rods with these various modifications have been fabricated. To date, thirty-four have been irradiated and the sixteen have been examined, This experience and effort has produced fruitful results: (1)Efficiency and reliability of the diving-bell type Helium venting mechanism (2)Efficiency of the flow induced vibration prevention mechanism (3)Efficiency of the improvement for scram damping mechanism (4)Clarification of absorvber-pellet-cladding-mechanical-interaction (ACMI)phenomena and preventive methods The fourth result listed above has been a subject of investigation for fifteen years in several countries, that is a main phenomena to dominate control rod life time. The results of this investigation of ACMI in absorber elements are summarized below: (a)In five of Joyo Mk-II control rods, cladding cracks were found in fifteen of the elements. These cracks were caused by a acceleration ACMI, due to BC fragments relocation. They occurred over a wide burnup range from 5E+26 Cap./m to 45E+26Cap./m in a nearly typical provability distribution. The cladding cracked because of its low ductility (approximately 1/4 lower than the uniform elongation of usual tensile testing for irradiated 316SS cladding) due to neutron irradiation and the ultra slow ACMI induced strain rate. (b)In this case the crack growth rate is extremely slow and the ACMI induced cracking in absorber elements do not influence either the reactor or plant operations. It is on this basis that a strict limitation to avoid the cladding crack is not necessary. According1y, it is suggested that a realistic design standard should consider the ACMI phenomena and the burnup limit be based on the nominal base calculation for average plastic strain use ...
; Sugikawa, Susumu; ; Miyoshi, Yoshinori; Miyauchi, Masakatsu; Izawa, Naoki
JAERI-Tech 96-058, 28 Pages, 1997/01
no abstracts in English
*; Tanaka, Keisuke*; *; Minakawa, Nobuaki; Morii, Yukio; *
Nihon Kikai Gakkai Rombunshu, A, 62(600), p.1924 - 1930, 1996/08
no abstracts in English
Wada, Yukio; Funasaka, Hideyuki; Myochin, Munetaka; Yamamoto, Kazunori; Harada, Hideo; ;
PNC TN8100 96-005, 16 Pages, 1996/01
no abstracts in English
Ishikawa, Isamu
Proc. of 11th KAIF/KNS Annual Conf., 0, p.611 - 619, 1996/00
no abstracts in English
Power Reactor and Nuclear Fuel Development Corporation
PNC TN9360 95-002, 98 Pages, 1995/11
no abstracts in English
Power Reactor and Nuclear Fuel Development Corporation
PNC TN9360 95-001, 104 Pages, 1995/11
no abstracts in English
1993) on nuclear material crossover researchKano, Shigeki; Tachi, Yoshiaki; ; ; Yoshida, Eiichi; Hirakawa, Yasushi
PNC TN9410 94-113, 70 Pages, 1994/04
(Purpose) This report describes the outline, research results obtained, interchange activities, etc. of the Phase I Program on the Nuclear Material Crossover Research, which has been conducted by related research institutes including PNC/OEC from 1989 through 1993 fiscal year, and shows the Phase II Program to be started from 1994 fiscal year. (Method) Crossover research programs, research results and interchange methods were decided through discussions at the crossover research comittee (chairman : Prof.M.Okamoto, TIT) in which PNC, JAERI, NRIM, NIRIM and NCLI were participated as main members. Forums, seminars, symposiums and workshops with domestic and foreign experts on materials research were set up as the opportunities for interchange. (Results) (1)As secretary institutes, PNC and JAERl planned eight times of forums, 3 times of seminars, twice of domestic symposiums, once of international symposium, five workshops with research institutes in France, Germany, Italy and the Netherland. The contacts with outside experts, collection of new information on advanced materials, receipt of test samples, achievement of collaborative research, etc. through these interchanges were much valuable for effective performance of PNC research. (2)The following results were obtained on PNC research. The prospects on creation of following advanced materials were obtained through these interchanges: (a)advanced ceramics having excellent corrosion resistance to sodium, (b)longer life neutron absorbing materials having higher resistance to cracking than BC, (c)high performance shielding materials having higher heat resistance than conventional materials. (3)Phase II Program to be started from 1994 fiscal year has been planned by main five institutes and authorized through the evaluation by two evaluation comittees organized separately by the crossover research comittee and PNC. (Conclusion) The prospects on creation of several advanced materials were obtained through ...
