Differential pressure rise event for filters of HTTR primary helium gas circulators, 1; Investigation of differential pressure rise event

Nemoto, Takahiro; Arakawa, Ryoki; Kawakami, Satoru; Nagasumi, Satoru; Yokoyama, Keisuke; Watanabe, Masashi; Onishi, Takashi; Kawamoto, Taiki; Furusawa, Takayuki; Inoi, Hiroyuki; et al.

JAEA-Technology 2023-005, 33 Pages, 2023/05

JAEA-Technology-2023-005.pdf:5.25MB

During shut down of the HTTR (High Temperature engineering Test Reactor) RS-14 cycle, an increasing trend of filter differential pressure for the helium gas circulator was observed. In order to investigate this phenomenon, the blower of the primary helium purification system was disassembled and inspected. As a result, it is clear that the silicon oil mist entered into the primary coolant due to the deterioration of the charcoal filter performance. The replacement and further investigation of the filter are planning to prevent the reoccurrence of the same phenomenon in the future.

Radiocesium distribution in the sediments of the Odaka River estuary, Fukushima, Japan

Hagiwara, Hiroki; Nakanishi, Takahiro; Konishi, Hiromi*; Tsuruta, Tadahiko; Misono, Toshiharu; Fujiwara, Kenso; Kitamura, Akihiro

Journal of Environmental Radioactivity, 220-221, p.106294_1 - 106294_9, 2020/09

https://doi.org/10.1016/j.jenvrad.2020.106294

Beam commissioning of the linac for iBNCT

Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11

http://www.pasj.jp/web_publish/pasj2016/proceedings/PDF/TUP1/TUP118.pdf

The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.

DT neutronics benchmark experiment on lead at JAEA-FNS

Ochiai, Kentaro; Kondo, Keitaro; Onishi, Seiki; Takakura, Kosuke; Sato, Satoshi; Abe, Yuichi; Konno, Chikara; Suzuki, Chihiro*; Yagi, Takahiro*

Journal of the Korean Physical Society, 59(2), p.1953 - 1956, 2011/08

https://doi.org/10.3938/jkps.59.1953

Lead is an important candidate material as multiplier of nuclear fusion reactor. Few DT neutron integral benchmark experiments were performed for lead so far. Therefore, we have carried out an integral benchmark experiment on lead at the DT neutron source facility of JAEA, FNS. A cubic lead assembly on a side of 45.3 cm was set up and was irradiated with the DT neutron source. Reaction rates of the Al(n,)Na, Nb(n,2n)Nb, Zr(n,2n)Zr and In(n,n')In reactions were measured as fast neutron spectrum indices in the assembly. A small NE213 spectrometer was also used for measurement of neutron spectra in the assembly. A Monte Carlo calculation code, MCNP5, was adopted to calculate the above neutron spectra and activation reaction rates. Nuclear data libraries, JENDL-3.3, ENDF/B-VII.0, JEFF-3.1 and FENDL-2.1, were used in the calculation. The calculation results of the three libraries except for JENDL-3.3 agreed with the measuring ones. In case of JENDL-3.3, some remarkable disagreements were found. From our investigations, it was pointed out that the inappropriate evaluation of the (n,2n) and inelastic cross sections of lead in JENDL-3.3 caused such disagreement.

Integral experiment on beryllium with DD neutrons for nuclear data benchmarking

Kondo, Keitaro; Ochiai, Kentaro; Tatebe, Yosuke; Yagi, Takahiro; Onishi, Seiki; Takakura, Kosuke; Sato, Satoshi; Konno, Chikara

Progress in Nuclear Science and Technology (Internet), 1, p.61 - 64, 2011/02

https://doi.org/10.15669/pnst.1.61

At the Fusion Neutronics Source (FNS) facility of JAEA we have conducted various integral experiments with DT neutrons for fusion reactor materials and have made a significant progress in the verification of their nuclear data. Recently we started a new series of integral experiments with DD neutrons at FNS in order to verify nuclear data relating to DD neutrons effectively. An integral experiment on beryllium with the DD neutron source will be presented in this conference. A beryllium pseudo-cylinder assembly of 45 cm in thickness and 63 cm in the diameter was built at the distance of 20 cm from the DD neutron source, and reaction rates of the In(n,n')In, Au(n,)Au and Li(n,)T reactions and a U fission rate were measured. The measured values were compared with calculations with the MCNP5 code and the latest nuclear data libraries; JENDL-3.3, ENDF/B-VII.0 and JEFF-3.1. A slight disagreement between the measurement and the calculation was found in the reaction rate of In, which is sensitive to neutrons above 0.3 MeV. We identified that the disagreement originated from the angular differential cross section data of the elastic scattering around 3 MeV and from the (n,2n) reaction cross section data near its threshold energy. The calculated reaction rates of Au, Li and U, which are sensitive to low energy neutrons, showed a large overestimation, which also appeared at the beryllium integral experiment with DT neutrons previously carried out at FNS. This problem has not been solved yet.

Experiment on synthesis of an isotope 112 by Pb + Zn reaction

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Katori, Kenji*; Koura, Hiroyuki; Kudo, Hisaaki*; et al.

Journal of the Physical Society of Japan, 76(4), p.043201_1 - 043201_5, 2007/04

https://doi.org/10.1143/JPSJ.76.043201

The production and decay of 112 has been investigated using a gas-filled recoil ion separator in irradiations of Pb targets with Zn beam at 349.5 MeV. We have observed two -decay chains that can be assigned to subsequent decays from 112 produced in the 208 Pb(Zn,n) reaction. After emitting four consecutive -particles, the both chains ended by spontaneous fission decays of Rf and decay energies and decay times of the both chains obtained in the present work agree well with those reported by a group at Gesellschaft fr Schwerionenforschung (GSI), Germany. The present result gives the first clear confirmation of the discovery of 112 and its -decay products Ds reported previously.

Ion beam effects on electrical characteristics of proton conductive polymer

Nagata, Shinji*; Konishi, Yoshitada*; Tsuchiya, Bun*; To, Kentaro*; Yamamoto, Shunya; Takahiro, Katsumi*; Shikama, Tatsuo*

Nuclear Instruments and Methods in Physics Research B, 257(1-2), p.519 - 522, 2007/04

https://doi.org/10.1016/j.nimb.2007.01.111

Effects of MeV ion irradiation on electrical characteristics of perfluorosulphonic polymer membrane have been studied. The DC electrical conductivity in dry condition increased of three orders of magnitude as a consequence of irradiation with MeV region H and He ion irradiation at a fluence of 2 10 ions/cm. The optical absorption in the ultra-violet region increased in the ion irradiated membrane due to the formation of fluorocarbon and peroxy radicals. The ion irradiation may form fluorocarbon and peroxy compounds and improve the transport property of protons in the membrane.

Hydrogen isotope retention of JT-60U W-shaped divertor tiles exposed to DD discharges

Shibahara, Takahiro*; Tanabe, Tetsuo*; Hirohata, Yuko*; Oya, Yasuhisa*; Oyaizu, Makoto*; Yoshikawa, Akira*; Onishi, Yoshihiro*; Arai, Takashi; Masaki, Kei; Okuno, Kenji*; et al.

Journal of Nuclear Materials, 357(1-3), p.115 - 125, 2006/10

https://doi.org/10.1016/j.jnucmat.2006.06.001

no abstracts in English

Experiment on the synthesis of element 113 in the reaction Bi(Zn,n)113

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Akiyama, Takahiro*; Goto, Shinichi*; Haba, Hiromitsu*; Ideguchi, Eiji*; Kanungo, R.*; Katori, Kenji*; Koura, Hiroyuki; et al.

Journal of the Physical Society of Japan, 73(10), p.2593 - 2596, 2004/10

https://doi.org/10.1143/JPSJ.73.2593

The isotope of the 113th element, 113, and its daughter nuclei, 111 and Mt, were obserbed, for the first time, in the Bi + Zn reaction at a beam energy of 349.1 MeV with a total dose of 1.610. The production cross section of 113 is deduced to be fb ( cm).

Labeling with radioactive rhenium for the purpose of the pain relief of cancerous bone metastasis

Ogawa, Kazuma*; Ono, Masahiro*; Fujioka, Yasushi*; Saji, Hideo*; Mukai, Takahiro*; Konishi, Junji*; Uehara, Tomoya*; Arano, Yasushi*; Onoma, Katsuyuki

Kaku Igaku, 37(5), P. 577, 2000/09

no abstracts in English