Study on the evaluation method to determine the radioactivity concentration in radioactive waste on Oarai Research and Development Institute (FY2020)

Asakura, Kazuki; Shimomura, Yusuke; Donomae, Yasushi; Abe, Kazuyuki; Kitamura, Ryoichi; Miyakoshi, Hiroyuki; Takamatsu, Misao; Sakamoto, Naoki; Isozaki, Ryosuke; Onishi, Takashi; et al.

JAEA-Review 2021-020, 42 Pages, 2021/10

JAEA-Review-2021-020.pdf:2.95MB

The disposal of radioactive waste from the research facility need to calculate from the radioactivity concentration that based on variously nuclear fuels and materials. In Japan Atomic Energy Agency Oarai Research and Development Institute, the study on considering disposal is being advanced among the facilities which generate radioactive waste as well as the facilities which process radioactive waste. This report summarizes a study result in FY2020 about the evaluation method to determine the radioactivity concentration in radioactive waste on Oarai Research and Development Institute.

Upgrade of the 3-MeV linac for testing of accelerator components at J-PARC

Kondo, Yasuhiro; Hirano, Koichiro; Ito, Takashi; Kikuzawa, Nobuhiro; Kitamura, Ryo; Morishita, Takatoshi; Oguri, Hidetomo; Okoshi, Kiyonori; Shinozaki, Shinichi; Shinto, Katsuhiro; et al.

Journal of Physics; Conference Series, 1350, p.012077_1 - 012077_7, 2019/12

https://doi.org/10.1088/1742-6596/1350/1/012077

We have upgraded a 3-MeV linac at J-PARC. The ion source is same as the J-PARC linac's, and the old 30-mA RFQ is replaced by a spare 50-mA RFQ, therefore, the beam energy is 3 MeV and the nominal beam current is 50 mA. The main purpose of this system is to test the spare RFQ, but also used for testing of various components required in order to keep the stable operation of the J-PARC accelerator. The accelerator has been already commissioned, and measurement programs have been started. In this paper, present status of this 3-MeV linac is presented.

Comprehensive evaluation system for environmental remediation of Fukushima; Toward integration of three components as a whole system

Saito, Hiroshi; Nozawa, Takashi; Takemiya, Hiroshi; Seki, Akiyuki; Matsubara, Takeshi; Saito, Kimiaki; Kitamura, Akihiro

JAEA-Review 2017-040, 34 Pages, 2018/03

JAEA-Review-2017-040.pdf:9.52MB

The accidents at Fukushima Daiichi Nuclear Power Station on March 11th 2011, released significant amount of radionuclide to the environment. It has migrated to the human habitation and raised concerns of possible effect on human health, and for that a lot of researches have been performed. JAEA created and opened "Database for Radioactive Substance Monitoring Data" for usage of obtained data. For accurate modelling and future forecast using numerical code and the data, "Supporting Environment for Processing Simulation Codes" has been operated. In addition, research results have been opened as Q&A style "Knowledge Base for Environmental Remediation" in JAEA's website. The "Comprehensive Evaluation System" composed of these components, should act more interrelated and integrated as one system. Besides, information dissemination is not enough to the outside. The report summarizes the current status, remaining issues and expected improvement of each component and the system.

The Muon linac for the precise measurement of muon g-2/EDM at J-PARC

Kondo, Yasuhiro; Hasegawa, Kazuo; Ito, Takashi; Artikova, S.; Otani, Masashi*; Mibe, Tsutomu*; Naito, Fujio*; Yoshida, Mitsuhiro*; Kitamura, Ryo*; Iwashita, Yoshihisa*; et al.

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.66 - 69, 2016/11

http://www.pasj.jp/web_publish/pasj2016/proceedings/PDF/MOOM/MOOM04.pdf

We are developing a muon linac for the measurement of the muon anomalous magnetic moment and search for the muon electric dipole moment to explore beyond the Standard Model of elementary particle physics. This muon linac accelerate from room temperature to 212 MeV with normalized transverse emittances of about 1.5 mm mrad. The muon linac consists of an ultra-slow muon source, a radio frequency quadrupole (RFQ) linac, an inter-digital H-mode drift tube linac (IH-DTL), a disk and washer coupled cavity linac (DAW CCL), and disk loaded structure (DLS) traveling-wave linac. In this paper, the status of the muon linac development, especially, the beam dynamics simulation is descried.

Study of annealing effect on crystal and local structures of doped zirconia using multi probe

Ito, Takanori*; Mori, Masashi*; Inukai, Manabu*; Nitani, Hiroaki*; Yamamoto, Takashi*; Miyanaga, Takashi*; Igawa, Naoki; Kitamura, Naoto*; Ishida, Naoya*; Idemoto, Yasushi*

Photon Factory News, 33(1), p.18 - 24, 2015/05

http://pfwww.kek.jp/publications/pfnews/33_1/saikin1.pdf

The effect of the annealing on the crystal and local structures of doped zirconia was investigated by multi-probe technique using synchrotron X-ray and neutron diffraction, and first principles calculation. It was revealed that the annealing process enhances the periodic distortion of some zirconia compounds by Rietveld/ maximum entropy methods applied to the SR-X-ray and neutron diffractions. In addition, the combined X-ray absorption spectroscopy and first-principles calculations results showed the ZrO polyhedra in zirconia were distorted by the annealing. Those results indicate that the degradation of oxide ionic conductivity by the annealing was related to the periodic distortion in zirconia.

Operating manipulator arm by robot suit HAL for remote in-cell equipment maintenance

Kitamura, Akihiro; Namekawa, Takashi; Hiramatsu, Kosuke*; Sankai, Yoshiyuki*

Nuclear Technology, 184(3), p.310 - 319, 2013/12

https://doi.org/10.13182/NT13-A24988

A remote control system to operate manipulator arm by robot suit HAL, hybrid assisted limb, is examined for in-cell equipment maintenance application. In this integrated system operator wear exoskeletal structured HAL and movement and intention of operator are transferred through computer system to the slave type manipulator arm. The system provides position control scheme and bioelectrical signals control scheme. In order to evaluate the effectiveness and usefulness of the system, we implemented remote handling experiments using mock up equipment and compared the performances of remote operation conducted by the abovementioned two schemes with that by 3D mouse control scheme. Among these three control schemes, bioelectrical signals control scheme had outperformed the others. Under the bioelectrical signals control scheme, the system achieved expected results in executing direct contact tasks of equipment maintenance with small operation time and small variation.

Full-coherent free electron laser seeded by 13th- and 15th-order harmonics of near-infrared femtosecond laser pulses

Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Togashi, Tadashi*; Fukami, Kenji*; et al.

Journal of Physics B; Atomic, Molecular and Optical Physics, 46(16), p.164006_1 - 164006_6, 2013/08

https://doi.org/10.1088/0953-4075/46/16/164006

By introducing 13th- (61.7 nm) and 15th-order harmonics (53.4 nm) of femtosecond laser pulses at 800 nm into an undulator of SCSS (SPring-8 Compact SASE Source) test accelerator at RIKEN, these harmonic pulses were amplified by a factor of more than 10 with a high contrast ratio through the interaction between accelerated electron bunches and the harmonic pulses. From numerical simulations of the amplification processes of high-order harmonic pulses in the undulator, optimum conditions of the electron bunch duration interacting with the high-order harmonic pulses were investigated for generating full-coherent and intense pulses in the extreme ultraviolet wavelength region.

In-cell maintenance by manipulator arm with 3D workspace information recreated by laser rangefinder

Kitamura, Akihiro; Nakai, Koji; Namekawa, Takashi; Watahiki, Masatoshi

Nuclear Engineering and Design, 241(7), p.2614 - 2623, 2011/07

https://doi.org/10.1016/j.nucengdes.2011.04.044

We developed a remote control system to display recreated three dimensional information of workspace from measured data obtained by laser rangefinder and to operate manipulator arm remotely. In order to evaluate the effectiveness and usefulness of developed system, we implemented remote handling experiments using mock up equipment and compared the performances of remote operation conducted by the present control system with that by the usual camera based control system. Impressions of operator on the performance of each system are collected and NASA TLX tests are conducted. It was observed that the present system reduced workload stresses and reinforced visual information during remote operation.

Development of polarization interferometer for Thomson scattering diagnostics in JT-60U

Hatae, Takaki; Howard, J.*; Ebizuka, Noboru*; Hirano, Yoichi*; Koguchi, Haruhisa*; Kitamura, Shigeru; Sakuma, Takeshi; Hamano, Takashi

Journal of Plasma and Fusion Research SERIES, Vol.8, p.680 - 684, 2009/09

A polarization interferometer based on the Fourier transform spectroscopy for the Thomson scattering diagnostics is being developed to evaluate the validity. At the first stage, a dual channel polarization interferometer utilizing a fixed-thickness birefringent plate is developed, and the target and ranges were 1 keV and 510 m, respectively. The electron temperature is successfully measured by the dual channel polarization interferometer in TPE-RX reversed field pinch machine, for the first time. The temperature of the polarization interferometer nearly agrees with that of the filter polychromator. At the second stage, we are developing a multichannel polarization interferometer employing a Wallaston prism to cover wider range of electron temperature. Interferograms of three kinds of light sources are measured by the multichannel polarization interferometer, and those spectra are reconstructed by Fourier transform. In the measurement of a blackbody radiation source using the multichannel polarization interferometer, both ideal and measured spectra agree within 8%.

Irradiation test of fuel containing minor actinides in the experimental fast reactor Joyo

Soga, Tomonori; Sekine, Takashi; Tanaka, Kosuke; Kitamura, Ryoichi; Aoyama, Takafumi

Journal of Power and Energy Systems (Internet), 2(2), p.692 - 702, 2008/00

https://doi.org/10.1299/jpes.2.692

The mixed oxide containing minor actinides (MA-MOX) fuel irradiation program is being conducted using Joyo. Two irradiation experiments were conducted in the MK-III 3rd operational cycle. Six prepared fuel pins included MOX fuel containing americium, MOX fuel containing americium and neptunium, and reference MOX fuel. The first test was conducted with high linear heat rates of 430 W/cm maintained during only 10 minutes in order to confirm whether or not fuel melting occurred. After 10 minutes irradiation in May 2006, the test subassembly was transferred to the hot cell facility and two test pins were replaced with dummy pins. The test subassembly loaded with the remaining four fuel pins was re-irradiated in Joyo for 24 hours in August 2006 to obtain re-distribution data on MA-MOX fuel. Linear heat rates for each pin were calculated using MCNP. Post irradiation examination of these pins to confirm the irradiation behavior of MA-MOX fuel is underway.