Study on hydrogen generation from cement solidified products loading low-level radioactive liquid wastes at Tokai Reprocessing Plant

Sato, Fuminori; Matsushima, Ryotatsu; Ito, Yoshiyuki

QST-M-16; QST Takasaki Annual Report 2017, P. 60, 2019/03

http://id.nii.ac.jp/1657/00074822/

Hydrogen gas generation by -radiation from cement solidified products loading low-level radioactive liquid waste generated at LWTF in Tokai Reprocessing Facility was studied.

Development of remote sensing technique using radiation resistant optical fibers under high-radiation environment

Ito, Chikara; Naito, Hiroyuki; Ishikawa, Takashi; Ito, Keisuke; Wakaida, Ikuo

JPS Conference Proceedings (Internet), 24, p.011038_1 - 011038_6, 2019/01

https://doi.org/10.7566/JPSCP.24.011038

A high-radiation resistant optical fiber has been developed in order to investigate the interiors of the reactor pressure vessels and the primary containment vessels at the Fukushima Daiichi Nuclear Power Station. The tentative dose rate in the reactor pressure vessels is assumed to be up to 1 kGy/h. We developed a radiation resistant optical fiber consisting of a 1000 ppm hydroxyl doped pure silica core and 4 % fluorine doped pure silica cladding. We attempted to apply the optical fiber to remote imaging technique by means of fiberscope. The number of core image fibers was increased from 2000 to 22000 for practical use. The transmissive rate of infrared images was not affected after irradiation of 1 MGy. No change in the spatial resolution of the view scope by means of image fiber was noted between pre- and post-irradiation. We confirmed the applicability of the probing system, which consists of a view scope using radiation-resistant optical fibers.

Evaluation of in-water wireless transmission system under the conditions simulated the severe accident

Otsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

http://doi.org/10.1109/NSSMIC.2017.8532843

no abstracts in English

Radiation-induced degradation of aqueous 2-chlorophenol assisted by zeolites

Kumagai, Yuta; Kimura, Atsushi*; Taguchi, Mitsumasa*; Watanabe, Masayuki

Journal of Radioanalytical and Nuclear Chemistry, 316(1), p.341 - 348, 2018/04

https://doi.org/10.1007/s10967-018-5762-z

We studied effect of adsorption and condensation by zeolites on radiation-induced degradation of aqueous 2-chlorophenol (2-ClPh). This study aims to demonstrate that the solid-phase extraction using zeolites has potential advantage in treatments of aqueous organic pollutants. Among three zeolites examined in this study, a mordenite type zeolite (HMOR) that has a high Si to Al ratio (127 3) exhibited preferable performance as the matrix for the 2-ClPh degradation. HMOR adsorbed far more 2-ClPh than the other zeolites, which have lower Si/Al ratios. The irradiation of HMOR induced degradation of adsorbed 2-ClPh into Cl and organic by-products. We found a significant increase in Cl production by HMOR. The yield of Cl production in the presence of HMOR was as high as the yield in aqueous solution of 2-ClPh at a concentration 10 times higher. The increased Cl production indicates that the high concentration of adsorbed 2-ClPh led to effective use of the adsorbed energy of HMOR.

Investigation of hydrogen gas generation by radiolysis for cement-solidified products of used adsorbents for water decontamination

Sato, Junya; Kikuchi, Hiroshi*; Kato, Jun; Sakakibara, Tetsuro; Matsushima, Ryotatsu; Sato, Fuminori; Kojima, Junji; Nakazawa, Osamu

QST-M-8; QST Takasaki Annual Report 2016, P. 62, 2018/03

http://repo.qst.go.jp/?action=repository_uri&item_id=34490

no abstracts in English

Development of a water purifier for radioactive cesium removal from contaminated natural water by radiation-induced graft polymerization

Seko, Noriaki*; Hoshina, Hiroyuki*; Kasai, Noboru*; Shibata, Takuya; Saiki, Seiichi*; Ueki, Yuji*

Radiation Physics and Chemistry, 143, p.33 - 37, 2018/02

https://doi.org/10.1016/j.radphyschem.2017.09.007

Hydrogen production by -ray irradiation from different types of zeolites in aqueous solution

Kumagai, Yuta; Kimura, Atsushi*; Taguchi, Mitsumasa*; Watanabe, Masayuki

Journal of Physical Chemistry C, 121(34), p.18525 - 18533, 2017/08

https://doi.org/10.1021/acs.jpcc.7b03532

H production by irradiation of zeolite-water mixtures was studied, to investigate effect of zeolites in the reaction process for H. Four different types of zeolites were examined comparatively under anoxic and under aerated conditions. High production yields of H were observed for the zeolites of high Al contents at low water fraction and under anoxic condition, compared to zeolites having lower Al contents. A comparison of the H yields in connection with chemical analysis of the zeolites suggests that extraframework Al species in the zeolites are involved in a reaction pathway for H. Meanwhile, under aerated condition and at high mixing ratio of water, the difference in H yield among the zeolites was suppressed and the yields of H were lower than those under anoxic condition probably due to HO produced by water radiolysis. The comparable H yields suggest another reaction pathway for H which is less dependent on the structure and composition of the zeolites.

Development of high-performance monitoring system under severe accident condition

Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Komanome, Hirohisa*; Miura, Kuniaki*; Ishihara, Masahiro

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 6 Pages, 2017/04

After the accident at the Fukushima Dai-ichi (1F) Nuclear Power Plant (NPP), the Japanese Government referred to "Enhancement of instrumentation to identify the status of the reactors and PCVs", in the report of Japanese government to the IAEA ministerial conference in June 2011. In response to these provisions, a research and development of a monitoring system for NPPs situations during severe accidents started in November 2012. The objectives of the R&D are composed of radiation-resistant monitoring camera, radiation-resistant in-water transmission system, and heat-resistant signal cable. For all the three objectives, the elemental technologies have been already developed and now trial system are being fabricated and tested under simulated conditions of severe accidents. The results will enable us to determine the basic specifications of the systems and to provide the information about application limits for users.

Degradation behavior of surface-mounted LED by irradiation

Takeuchi, Tomoaki; Otsuka, Noriaki; Uehara, Toshiaki; Kumahara, Hajime*; Tsuchiya, Kunihiko

QST-M-2; QST Takasaki Annual Report 2015, P. 80, 2017/03

http://repo.qst.go.jp/?action=repository_uri&item_id=30337

no abstracts in English

Gamma radiation resistance of spin Seebeck devices

Yagmur, A.*; Uchida, Kenichi*; Ihara, Kazuki*; Ioka, Ikuo; Kikkawa, Takashi*; Ono, Madoka*; Endo, Junichi*; Kashiwagi, Kimiaki*; Nakashima, Tetsuya*; Kirihara, Akihiro*; et al.

Applied Physics Letters, 109(24), p.243902_1 - 243902_4, 2016/12

https://doi.org/10.1063/1.4971976

Thermoelectric devices based on the spin Seebeck effect (SSE) were irradiated with gamma () rays with the total dose of around 310 Gy in order to investigate the -radiation resistance of the devices. To demonstrate this, Pt/NiZnFeO/Glass and Pt/BiYFeO/GdGaO SSE devices were used. We confirmed that the thermoelectric, magnetic, and structural properties of the SSE devices are not affected by the -ray irradiation. This result demonstrates that SSE devices are applicable to thermoelectric generation even in high radiation environments.