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Kamikawa, Yutaka; Suzuki, Makoto; Agake, Toshiki; Murakami, Takahiko; Morita, Yusuke; Shiina, Hidenori; Fukushima, Manabu; Hirane, Nobuhiko; Ouchi, Yasuhiro
JAEA-Technology 2023-030, 57 Pages, 2024/03
JAEA-Technology-2023-030.pdf:1.93MB
Owing to the publication of the latest data about aircraft crashes by Nuclear Regulation Authority (NRA), it was necessary to re-evaluate the probabilities of aircraft crashes for Nuclear Science Research Institute (NSRI). By using of the assessment method provided in "Regulatory Guide of the Assessment Standard for Probability of Airplane Crash on a Nuclear Power Reactor Facility", we re-evaluated the probabilities of aircraft crashes against the nuclear facilities in NSRI. As a result of the evaluations, the sum of the probabilities of aircraft crashes against Waste Treatment Facilities (maximum probability among all nuclear facilities in NSRI) is 5.68
10
(times/(reactor 
year)) which is lower than 10
(times/(reactor year)) that is the assessment criterion whether aircraft crashes is considered to be "anticipated external human induced events" in design basis or not.
Suto, Toshiyuki; Fukushima, Manabu*
JAEA-Data/Code 2011-021, 91 Pages, 2012/02
JAEA-Data-Code-2011-021.pdf:3.57MB
Future reprocessing facilities are considered to treat not only LWR uranium fuels but also LWR-MOX fuels and even FBR fuels. These spent fuels have various enrichments, isotopic compositions of plutonium. In order to make reasonable design and management of criticality safety for such multi-fuel reprocessing facilities, there needs to be critiricality safety data with a multiple of enrichments, isotopic compositions of plutonium. The authors calculated subcritical dimensions of uranium/plutonium mixed nitrate solution with a multiple set of enrichments and isotopic compositions of plutonium for cylinder, slab, and annular geometries and arranged the results in tables and graphs which are usable for the criticality safe design study of future reprocessing facilities. In addition, some findings useful for selecting criticality safety control methods were summarized.
Fukushima, Manabu; Owada, Minoru; Ota, Kazunori; Takeuchi, Masaki; Goto, Shingo; Imahashi, Masaki; Terakado, Yoshibumi
JAEA-Technology 2010-028, 24 Pages, 2010/09
JAEA-Technology-2010-028.pdf:1.01MB
The cooling tower of the JRR-3's secondary cooling system is used to emit the heat from the core into the atmosphere. The appropriate maintenance of the cooling tower has helped the safe and stable reactor operation. Temperature of the secondary coolant had controlled constantly by changing the number of cooling fans. But, just after the number of fans changed, the temperature changed transiently and consequently the reactor thermal power changed. In order to amend this some weakness, the control system has improved to change the speed of fans constantly. The maintenance and improvement activities with the records of inspection are compiled to be utilized for future work.
Oba, Toshinobu; Fukushima, Manabu; Takeuchi, Masaki; Uno, Yuki; Owada, Minoru; Terakado, Yoshibumi
JAEA-Technology 2010-020, 31 Pages, 2010/07
JAEA-Technology-2010-020.pdf:1.33MB
Japan research reactor No.3 (JRR-3) has a heavy water tank. The heavy water tank surrounds the reactor core to use thermalize neutrons for experiments. The heavy water cooling system removes the heat generated by 
ray in the heavy water reflector. The heavy water cooling system is composed of the cooling system and the helium gas system. The helium gas system has an important role of helium gas circulation. The helium gas system also has a role to recombine deuterium gas and oxygen gas. We had overhauled the helium compressor regularly and replaced consumable parts. However, in recent year, the helium compressor had sometimes stopped by the leakage of seal oil. In 2007, we refurbished the helium compressor with new one. This report describes refurbishment of helium compressor.
Ichimura, Toshiyuki; Suwa, Masayuki; Fukushima, Manabu; Oba, Toshinobu; Nemoto, Yoshinori; Terakado, Yoshibumi
Proceedings of 12th International Group on Research Reactors (12th IGORR) (USB Flash Drive), 8 Pages, 2009/10
Ota, Kazunori; Ikekame, Yoshinori; Owada, Minoru; Fukushima, Manabu; Oba, Toshinobu; Takeuchi, Masaki; Imahashi, Masaki; Murayama, Yoji
JAEA-Technology 2008-023, 31 Pages, 2008/03
JAEA-Technology-2008-023.pdf:3.3MB
JRR-3 uses shell and tube heat exchangers. The secondary coolant flushes into the tubes and the primary coolant flows outside of the tubes. The heat exchangers are cleaned with the ball-cleaning method, which is a method to clean inside of the tubes by passing the sponge balls with secondary coolant. Decline in the performance of heat exchanger could rise temperature of the primary coolant and then influence the safe and stable reactor operation. The effective way of ball-cleaning for JRR-3 heat exchangers is examined based on past cleaning data. The results show the optimal ball size and the way to determine the cleaning time.
Sato, Wakaei*; Fukushima, Manabu*;
JNC TN9400 2001-026, 90 Pages, 2000/09
JNC-TN9400-2001-026.pdf:2.61MB
A comprehensive study to evaluate and accumulate the abundant results of fast reactor physics is now in progress at O-arai Engineering Center to improve analytical methods and prediction accuracy of nuclear design for large fast breeder cores such as future commercial FBRs. The present report summarizes the analytical results of sample reactivity experiments at ZPPR-9 core, which has not been evaluated by the latest analytical method yet. The intention of the work is to extend and further generalize the standard data base for FBR core nuclear design. The analytical results of the sample reactivity experiments (samples: PU-30, U-6, DU-6, SS-1 and B-1) at ZPPR-9 core in JUPITER series, with the latest nuclear data libraly JENDL-3.2 and the analytical method which was established by the JUPITER analysis, can be concluded as follows: The region-averaged final C/E values generally agreed with unity within 5% differences at the inner core region. However, the C/E values of every sample showed the radial space-dependency increasing from center to core edge, especially the discrepancy of B-1 was the largest by 10%. Next, the influence of the present analytical results for the ZPPR-9 sample reactivity to the cross-section adjustment was evaluated. The reference case was a unified cross-section set ADJ98 based on the recent JUPITER analysis. As a conclusion, the present analytical results have sufficient physical consistency with other JUPITER data, and possess qualification as a part of the standard data base for FBR nuclear design.
Okawachi, Yasushi; Fukushima, Manabu*
JNC TN9400 99-051, 100 Pages, 1999/05
ORIGEN2 is one of the most widely-used burnup analysis code in the world. This code has one-grouped cross section libraries compiled for various types of reactors. However, these libraries have some problems. One is that these libraries were developed from old nuclear data libraries (ENDF/B-IV,V) and the other is that core and fule designs from which these libraries are generated do not match the current analysis. In order to solve the probrems, analysis tool is developed for generating ORIGEN2 library from JENDL-3.2 considering multi-energy neutron spectrum. And eight new libraries are prepared using this tool for analysis of sodium-cooled FBR. These new libralies are prepared for eight kinds of cores in total. Seven of them are made by changing core size (small core 
large core), fuel type (oxide, nitride, metal) and Pu vector as a parameter. The eighth one is a Pu burner core. Burnup calculation using both new and original libraries, shows large difference in buildup or depletion numbers of nuclides among the libraries. It is estimated that the analysis result is greatly influenced by the neutron spectrum which is used in collapse of cross section. By using this tool or new libraries, it seems to improve evaluation accuracy of buildup or depletion numbers of nuclides in transmutation research on FBR fuel cycle.
Oba, Toshinobu; Owada, Minoru; Fukushima, Manabu; Takeuchi, Masaki; Uno, Yuki; Murayama, Yoji
no journal, ,
no abstracts in English
Wakai, Eiichi; Takada, Fumiki; Takaya, Shigeru; Kato, Shoichi; Kitazawa, Sin-iti; Okubo, Nariaki; Suzudo, Tomoaki; Fujii, Kimio; Yoshitake, Tsunemitsu; Kaji, Yoshiyuki; et al.
no journal, ,
no abstracts in English
Nakazaki, Katsutoshi; Suto, Toshiyuki; Kosaka, Ichiro; Fukushima, Manabu*
no journal, ,
no abstracts in English
Suwa, Masayuki; Fukushima, Manabu; Terunuma, Noriaki; Ota, Kazunori; Murayama, Yoji
no journal, ,
no abstracts in English
Ishizaki, Katsuhiko; Ota, Kazunori; Takeuchi, Masaki; Imahashi, Masaki; Fukushima, Manabu
no journal, ,
no abstracts in English
Tanaka, Hisashi*; Chen, R.*; Asai, Miyuki*; Fukushima, Chikako*; Kawamoto, Toru*; Ishizaki, Manabu*; Kurihara, Masato*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
Hexacyanoferrate metal Complex (MHCF) is well-known as adsorption materials for Cesium ion. We have developed the effective processing method by making MHCF of nano particle ink. In this paper, we investigated the effect of the presence of other metal cations on electrochemical adsorption and desorption of cesium.
Chen, R.*; Tanaka, Hisashi*; Fukushima, Chikako*; Asai, Miyuki*; Kawamoto, Toru*; Kurihara, Masato*; Ishizaki, Manabu*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
Transition metal hexacyanoferrates (MHCFs) are preferred to be competitive ion exchangers over other materials due to their selectivity and high capacity. CuHCF
has been much used as precipitants for alkali metal cations, especially cesium, to remove them from aqueous radioactive wastes. Instated of the conventional adsorption by using copper hexacyanoferrate powder, we developed and coated the CuHCF nanoparticles on the electrode substance, and then performed Cs removal in an electrochemical column System. The objective of this study was to develop a nanoparticle film of CuHCF for Cs removal and to suggest a promising column technology for sequential removal of actual radiocesium wastewater.