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Tokunaga, Sho; Horiguchi, Hironori; Nakamura, Takemi
JAEA-Technology 2023-001, 37 Pages, 2023/05
JAEA-Technology-2023-001.pdf:1.39MB
The cold neutron source (CNS) of the research reactor JRR-3 converts thermal neutrons generated in the reactor into low-energy cold neutrons by moderating them with liquid hydrogen stored in the moderator cell. Cold neutrons generated by the CNS are transported to experimental instruments using neutron conduits, and are used for many studies of physical properties, mainly in life science, polymer science, environmental science, etc. Improvement of cold neutron intensity is essential to maintain competitiveness with the world's research reactors in neutron science, and we are developing a new CNS that incorporates new knowledge. The current moderator cell for the CNS of JRR-3 is a stainless-steel container which is a canteen bottle type, and the cold neutron intensity can be improved by changing the material and shape. Therefore, the basic specifications of the new moderator cell were changed to aluminum alloy which has a smaller neutron absorption cross section, and the shape was optimized using a Monte Carlo code MCNP. Since these changes in specifications will result in changes in heat generation and heat transfer conditions, the CNS of JRR-3 was re-evaluated in terms of self-regulating characteristic, heat transport limits, heat resistance and pressure resistance, etc., to confirm its feasibility in thermal-hydraulic design. This report summarizes the results of the thermal-hydraulic design evaluation of the new moderator cell.
Ishitsuka, Etsuo; Sakamoto, Naoki*
Physical Sciences and Technology, 6(2), p.60 - 63, 2019/12
Tritium release into the primary coolant of the research and test reactors during operation had been studied, and it is found that the recoil release from chain reaction of 
Be is dominant. To reduce tritium concentration of the primary coolant, feasibility study of the tritium recoil barrier for the beryllium neutron reflectors was carried out, and the tritium recoils of various materials were calculated by PHITS. From these calculation results, it is clear that the thickness of tritium recoil barrier depends on the material and 20
40 
m is required for three orders reduction.
Ishitsuka, Etsuo; Kenzhina, I.*; Okumura, Keisuke; Ho, H. Q.; Takemoto, Noriyuki; Chikhray, Y.*
JAEA-Technology 2018-010, 33 Pages, 2018/11
JAEA-Technology-2018-010.pdf:2.58MB
As a part of study on the mechanism of tritium release to the primary coolant in research and testing reactors, tritium recoil release rate from Li and U impurities in the neutron reflector made by beryllium, aluminum and graphite were calculated by PHITS code. On the other hand, the tritium production from Li and U impurities in beryllium neutron reflectors for JMTR and JRR-3M were calculated by MCNP6 and ORIGEN2 code. By using both results, the amount of recoiled tritium from beryllium neutron reflectors were estimated. It is clear that the amount of recoiled tritium from Li and U impurities in beryllium neutron reflectors are negligible, and 2 and 5 orders smaller than that from beryllium itself, respectively.
Ishitsuka, Etsuo; Kenzhina, I. E.*; Okumura, Keisuke; Takemoto, Noriyuki; Chikhray, Y.*
JAEA-Technology 2016-022, 35 Pages, 2016/10
JAEA-Technology-2016-022.pdf:3.73MB
As a part of study on the mechanism of tritium release to the primary coolant in research and testing reactors, the calculation methods by PHITS code is studied to evaluate the recoil tritium release rate from beryllium core components. Calculations using neutron and triton sources were compared, and it is clear that the tritium release rates in both cases show similar values. However, the calculation speed for the triton source cases is two orders faster than that for the neutron source case. It is also clear that the calculation up to history number per unit volume of 2
10
(cm
) is necessary to determine the recoil tritium release rate of two effective digits precision. Furthermore, the relationship between the beryllium shape and recoil tritium release rate using the triton sources was studied. Recoil tritium release rate showed linear relation to the surface area per volume of beryllium, and the recoil tritium release rate showed about half of the conventional equation value.
Arai, Masaji; Tamura, Itaru; Hazawa, Tomoya
JAEA-Technology 2015-010, 52 Pages, 2015/05
JAEA-Technology-2015-010.pdf:7.11MB
In the Department of Research Reactor and Tandem Accelerator, developments of high-performance CNS moderator vessel that can produce cold neutron intensity about two times higher compared to the existing vessel have been performed in the second medium term plans. We compiled this report about the technological development to solve several problems with the design and manufacture of new vessel. In the present study, design strength evaluation, mockup test, simulation for thermo-fluid dynamics of the liquid hydrogen and strength evaluation of the different-material-bonding were studied. By these evaluation results, we verified that the developed new vessel can be applied to CNS moderator vessel of JRR-3.
Needs Research Task Force for Next Research Reactor
JAEA-Review 2014-054, 43 Pages, 2015/03
JAEA-Review-2014-054.pdf:6.57MB
JRR-3 has been operated for more than 25 years for that it is time to investigate the role of a next research reactor. A task force under the Committee for Promotion of JRR-3 Neutron Beam Application has been organized by Department of Research Reactor and Tandem Accelerator to survey neutron beam application trends in the future. This is a report on the survey results and users' requirements for the next research reactor have been summarized in this report carried by the task force.
Advanced Science Research Center; Neutron Science Research Center
JAERI-Review 2005-045, 191 Pages, 2005/09
JAERI-Review-2005-045.pdf:17.2MB
This issue summarizes research progress in neutron science at Japan Atomic Energy Research Institute (JAERI) by utilizing the research reactor JRR-3 during the period between April 1, 2004 and March 31, 2005. This report contains highlights in research by 13 neutron research groups at JAERI and 91 summary articles.
Fujii, Yasuhiko
Genshiryoku eye, 51(9), p.18 - 19, 2005/09
no abstracts in English
Fujii, Yasuhiko
Hoshasen To Sangyo, (107), p.2 - 3, 2005/09
no abstracts in English
Morii, Yukio; Imase, Hajime*
Hoshasen To Sangyo, (107), p.52 - 55, 2005/09
no abstracts in English
Advanced Science Research Center; Neutron Science Research Center
JAERI-Review 2005-013, 161 Pages, 2005/03
JAERI-Review-2005-013.pdf:13.65MB
This issue summarizes research progress in neutron scattering at 
apan 
tomic 
nergy 
esearch 
nstitute (JAERI) by utilizing the research reactor JRR-3 during the period between April 1, 2003 and March 31, 2004.
Yasuda, Ryo; Matsubayashi, Masahito; Nakata, Masahito; Matsue, Hideaki; Nakanishi, Tomoko
Dai-5-Kai Hoshasen Ni Yoru Hihakai Hyoka Shimpojiumu Koen Rombunshu, p.31 - 34, 2005/02
Neutron radiography is an effectively nondestructive tool for inspection of irradiated nuclear fuels and materials. Neutron CT an neutron imaging plate methods, which are advanced techniques in the neutron radiography, enabled to obtain cross-section images and to evaluate an amount of the element compositions. This paper describes results of those methods using unirradiated fuels and materials and discussed the practicability of those methods to irradiated fuels and materials.
Tamura, Itaru; Suzuki, Masatoshi; Hazawa, Tomoya; Moriai, Atsushi; Hori, Naohiko; Sasajima, Fumio; Soyama, Kazuhiko
Nuclear Instruments and Methods in Physics Research A, 529(1-3), p.234 - 237, 2004/08
Times Cited Count：4 Percentile：30.85(Instruments & Instrumentation)Thermal neutron guides at JRR-3 reactor have been upgraded from Nickel mirrors to Ni/Ti multilayer supermirrors. We performed the characteristics experiment of neutron beams transmitted through supermirror neutron guides. Neutron fluxes at the end of the thermal neutron guides were measured by the gold foil activation method on March 2003. We have confirmed that neutron fluxes at the end of thermal neutron guide increases by 6 times. The neutron spectra were also measured at the end of the thermal neutron guides by the time-of-flight method. The wavelength range for the neutron beam is extended and the shorter wavelength neutrons, which had been filtered by the characteristics of curved neutron guides before upgrade, were observed. In this paper, we have performed several Monte Carlo simulation codes using the McStas package in the consideration of the performance of fabricated supermirrors and its alignment errors for the purpose of estimation of instruments performance. We discuss the comparison of the experimental results with results of simulation.
-ray analysis using 
-standardizationMatsue, Hideaki; Yonezawa, Chushiro
Bunseki Kagaku, 53(7), p.749 - 751, 2004/07
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)Multi-element determination in reference materials of soils (JASC401, JASC411) and sediments (NMIJ CRM 7302-a, NMIJ CRM 7303-a), which were prepared at the Japan Society for Analytical Chemistry and the National Institute of Advanced Industrial Science and Technology of the National Metrology Institute of Japan, respectively, has been carried out by neutron-induced prompt -ray analysis (PGA) using standard addition and -standardization methods. Firstly, absolute Ti concentrations in the samples were determined accurately by the standard addition method. Secondly, relative multi-element concentrations were determined by the -standardization method. Finally, absolute multi-element concentrations were obtained by normalizing the relative multi-element concentrations with the absolute Ti concentration in the samples. The 15 elements such as H, B, Na, Si, S, Cl, K, Ca, Ti Cr, Mn, Fe, Cd, Sm and Gd were determined by the -PGA. Analytical results of these reference materials agreed with the certified or reference values within about 10%.
Subcommittee for Neutron Beam Utilization; Status and Future Upgrades of the Facilities and Instruments
JAERI-Review 2003-037, 88 Pages, 2004/02
JAERI-Review-2003-037.pdf:6.98MB
The refurbished JRR-3 reached critical in March 1990, and the facilities were opened to the general user program in June 1991. Since then the improved specification and the increase of the beam flux of JRR-3 made it recognized as one of the top four research reactors in the world. Despite the ten fruitful years of achievements in research activities performed at JRR-3, it is indispensable to continuously upgrade and improve research facilities in order to maintain our standard of excellence in the research activities. It is also important that the high intensity proton accelerator project (J-PARC project) is progressing in the same JAERI site. Under these circumstances surrounding the JRR-3 facility, a task force under the neutron beam utilization committee was formed in 2001 and assigned to recommend the necessary upgrade and improvements of reactor facilities as well as neutron scattering instruments in JRR-3. This report summarizes analysis and discussions carried out in the task force during these two years, and describes recommendations from the task force.
Research Reactor Utilization Division
JAERI-Review 2003-019, 484 Pages, 2003/07
JAERI-Review-2003-019.pdf:29.68MB
no abstracts in English
Center for Neutron Science; Advanced Science Research Center
JAERI-Review 2002-002, 40 Pages, 2002/03
JAERI-Review-2002-002.pdf:4.03MB
no abstracts in English
Sakurai, Fumio; Horiguchi, Yoji; Kobayashi, Shinsho; Takayanagi, Masaji
Physica B; Condensed Matter, 311(1-2), p.7 - 13, 2002/01
Times Cited Count：9 Percentile：45.19(Physics, Condensed Matter)no abstracts in English
Matsubayashi, Masahito; Hibiki, Takashi*; Mishima, Kaichiro*
Nondestructive Testing and Evaluation, 16(2-6), p.267 - 275, 2001/01
no abstracts in English
Sasajima, Fumio; Sawahata, Hiroyuki*; Onizawa, Koji*; Ichimura, Shigeju; Otomo, Akitoshi; Ito, Yasuo*; Takayanagi, Masaji
JAERI-Tech 2000-073, 49 Pages, 2000/12
JAERI-Tech-2000-073.pdf:4.43MB
no abstracts in English
