Assessment of probability of aircraft crashes for Nuclear Science Research Institute

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 5.6810 (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.

New measurement system based on small-angle neutron scattering for structural analysis of light-responsive materials

Iwase, Hiroki*; Akamatsu, Masaaki*; Inamura, Yasuhiro; Sakaguchi, Yoshifumi*; Morikawa, Toshiaki*; Kasai, Satoshi*; Ouchi, Keiichi*; Kobayashi, Kazuki*; Sakai, Hideki*

Journal of Applied Crystallography, 56(1), p.110 - 115, 2023/02

https://doi.org/10.1107/S1600576722011104

With the increasing importance of light-responsive materials, it is vital to analyze the relationship between function and structural changes induced by light irradiation. Small-angle scattering (SAS) is effective for such structural analysis. However, quantitatively capturing local molecular structure formation and molecular reactions at a scale of less than 1 nm via SAS is difficult. In this study, to analyze the structure of non-equilibrium phenomena in light-responsive materials, a new sample environment has been developed for a time-of-flight small- and wide-angle neutron scattering instrument (TAIKAN), comprising a UV-Vis irradiation system, UV-Vis absorption measurement equipment and photodetector. Simultaneous measurement of small-angle neutron scattering and UV-Vis absorption was achieved. This system was used to demonstrate the in situ observation of UV-Vis irradiation-induced structural change of micelles formed by a light-responsive surfactant sample in an aqueous solution.

Cryogenic sample environments shared at the MLF, J-PARC

Kawamura, Seiko; Takahashi, Ryuta*; Ishikado, Motoyuki*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ouchi, Keiichi*; Kira, Hiroshi*; Kambara, Wataru*; Aoyama, Kazuhiro*; Sakaguchi, Yoshifumi*; et al.

Journal of Neutron Research, 21(1-2), p.17 - 22, 2019/05

https://doi.org/10.3233/JNR-190106

The Cryogenics and Magnets group in the Sample Environment team is responsible for operation of cryostats and magnets for user's experiments at the MLF in J-PARC. We have introduced a top-loading He cryostat, a bottom-loading He cryostat, a dilution refrigerator insert and a superconducting magnet. The frequency of use of them dramatically becomes higher in these two years, as the beam power and the number of proposal increase. To respond such situation, we have made efforts to enhance performance of these equipment as follows. The He cryostat originally involves an operation software for automatic initial cooling down to the base temperature and automatic re-charge of He. Recently we made an additional program for automatic temperature control with only the sorb heater. Last year, a new outer vacuum chamber of the magnet with an oscillating radial collimator (ORC) was fabricated. The data quality was drastically improved by introducing this ORC so that the magnet can be used even for the inelastic neutron scattering experiments.

Overview of high-pressure neutron beamline, PLANET, and practical aspects of the experiments

Hattori, Takanori; Sano, Asami; Arima, Hiroshi*; Funakoshi, Kenichi*; Abe, Jun*; Machida, Shinichi*; Okazaki, Nobuo*; Ouchi, Keiichi*; Inamura, Yasuhiro

Koatsuryoku No Kagaku To Gijutsu, 26(2), p.89 - 98, 2016/06

https://doi.org/10.4131/jshpreview.26.89

PLANET is a high-pressure neutron beamline constructed at pulsed-neutron source in Materials and Life Science Facility (MLF) in J-PARC. The six-axis multi-anvil press designed for time of flight (TOF) neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators that eliminate parasitic scattering from the high-pressure cell. The high performance of the diffractometer for the resolution ( 0.6%) and the accessible d-spacing range (0.2 - 8.4 ) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.

Beam monitoring system for RFQ test stand of J-PARC linac

Miyao, Tomoaki*; Miura, Akihiko; Kondo, Yasuhiro; Morishita, Takatoshi; Sugimura, Takashi*; Ouchi, Nobuo; Oguri, Hidetomo; Maruta, Tomofumi*; Naito, Fujio

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1049 - 1052, 2014/06

http://www.pasj.jp/web_publish/pasj10/proceedings/PDF/SUP0/SUP066.pdf

In J-PARC linac, a project for energy and intensity upgrade has been progressed using 50 mA RFQ(Radio-Frequency-Quadrupole) linac cavity. Because the RFQ had already fabricated, test stand for its performance test was newly produced. In the test stand, we designed and fabricated the monitoring system including beam current monitors for the beam transmission measurement and the beam phase monitors for the energy measurement. We will refer the detail of the monitoring system and the data obtained during the performance test. New testing devices are also mentioned.

Maintenance of the pump for the primary cooling system in JRR-3

Ouchi, Yasuhiro; Ito, Masatoshi; Oba, Toshinobu; Kawamata, Satoshi; Ishizaki, Katsuhiko

JAEA-Technology 2009-038, 38 Pages, 2009/07

JAEA-Technology-2009-038.pdf:2.87MB

The primary cooling system of JRR-3 is one of important facility which removes heat from reactor core. Therefore, it is necessary for safe and stable reactor operation to keep performance of four pumps which are main equipments of primary cooling system. These four pumps have been checked and maintained appropriately since the operation of JRR-3 started. Maintenance items and its records of primary cooling pumps are reported in this paper. Furthermore, aging problems of primary cooling pumps is investigated to contribute to management for maintenance of primary cooling pumps.

First test results for the ITER central solenoid model coil

Kato, Takashi; Tsuji, Hiroshi; Ando, Toshinari; Takahashi, Yoshikazu; Nakajima, Hideo; Sugimoto, Makoto; Isono, Takaaki; Koizumi, Norikiyo; Kawano, Katsumi; Oshikiri, Masayuki*; et al.

Fusion Engineering and Design, 56-57, p.59 - 70, 2001/10

https://doi.org/10.1016/S0920-3796(01)00235-6

no abstracts in English

None

Ouchi, Masaru; ; Sukegawa, Yasuhiro*; Miyo, Hiroaki;

PNC TN8410 91-176, 14 Pages, 1991/12

PNC-TN8410-91-176.pdf:0.5MB

None

Preparation for MOX powder sea transport by JAEA

Ouchi, Yuichiro; Kitamura, Takafumi; Shibata, Kan; Take, Tokuo*; Kamino, Yoshikazu*; Kawahara, Yasuhiro*

no journal, , 

JAEA is planning to procure MOX powder from the Rokka-sho Reprocessing Plant (RRP) of the JNFL in Aomori prefecture, as raw material to fabricate reloaded-fuel for the prototype fast breeder reactor "MONJU" and the experimental reactor "JOYO" at about 2014. A development of new packaging and a preparation of specialized transport system for responding to requirements of Category I nuclear materials have been implemented. The design of the new packaging started in 2002. A series of prototype tests using a prototype packaging has been con-ducted: heat convection test, handling test in RRP, and regulation tests according to the requirements for Type B(U)F package specified in the TS-R-1 of the IAEA safe transport regulations. The design of the dedicated transport container was conducted to accommodate as many packages as possible, based on an ISO 20-foot container. An assessment of sea transport for MOX powder was also conducted, as part of the safety assessment during transport by ship.

THz tomography of photo-induced carrier based on pump-probe spectroscopy in counter-propagation geometry

Tsubouchi, Masaaki; Nagai, Masaya*; Oshima, Yasuhiro*

no journal, , 

We have proposed a novel technique for the THz tomography of photo-induced carrier based on the optical-pump THz-probe reflection spectroscopy with the counter-propagated pump and probe pulses. We have experimentally demonstrated it with silicon. The obtained complex reflection can be reproduced by the exact solution of the Maxwell equations.