A Simple method to create gamma-ray-source spectrum for passive gamma technique

Shiba, Tomooki; Maeda, Shigetaka; Sagara, Hiroshi*; Ishimi, Akihiro; Tomikawa, Hirofumi

Energy Procedia, 131, p.250 - 257, 2017/12

https://doi.org/10.1016/j.egypro.2017.09.446

In the present paper, the ray source data was developed for the debris composition based on "best estimates", and the subsequent photon transportation calculation was performed to evaluate the leakage ray spectra according to the fuel debris. Since the creation of the line spectrum source requires a great deal, we have developed the relatively simple but accurate enough method to build up ray source, coupling of baseline spectra evaluated by ORIGEN2 code and several line spectra of interest. One of the advantages of the method is taking bremsstrahlung X rays into consideration by utilizing the bremsstrahlung libraries of ORIGEN2. The new ray source was used to calculate the detector response of HPGe detector and the results was compared as a benchmark with experimental measurement results of irradiated fuel pins. As the result, the simulated ray spectrum shape agreed well with the shape of ray spectrum obtained by the experiment.

Characterization study of four candidate technologies for nuclear material quantification in fuel debris at Fukushima Daiichi Nuclear Power Station (Interim report)

Nagatani, Taketeru; Komeda, Masao; Shiba, Tomooki; Maeda, Makoto; Nauchi, Yasushi*; Sagara, Hiroshi*; Kosuge, Yoshihiro*; Kureta, Masatoshi; Tomikawa, Hirofumi; Okumura, Keisuke; et al.

Proceedings of INMM 57th Annual Meeting (Internet), 10 Pages, 2016/07

Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

Tomita, Masanori*; Matsumoto, Hideki*; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke*; Maeda, Munetoshi*; Kobayashi, Yasuhiko

Life Sciences in Space Research, 6, p.36 - 43, 2015/07

https://doi.org/10.1016/j.lssr.2015.06.004

A radiation-induced bystander response is generally known as a cellular response induced in unirradiated cell by receiving bystander signaling factors released from directly irradiated cells of a cell population. Bystander responses induced by high-LET heavy ions at low fluence are an important problem concerning the health of astronauts in the space environment. Here we set out NO-mediated bystander signal transductions induced by high-LET heavy-ion microbeam irradiation in normal human fibroblasts. Our findings suggest that Akt- and NF-B-dependent signaling pathway involving COX-2 plays an important role in the NO-mediated high-LET heavy-ion-induced bystander responses. Additionally, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells, which are distinguish form directly irradiated cells.

Effect of radial zoning of Am content on homogenization of denatured Pu with broad range of neutron energy based on U irradiation test in the experimental fast reactor Joyo

Shiba, Tomooki*; Sagara, Hiroshi*; Onishi, Takashi; Koyama, Shinichi; Maeda, Shigetaka; Han, C. Y.*; Saito, Masaki*

Annals of Nuclear Energy, 51, p.74 - 80, 2013/01

https://doi.org/10.1016/j.anucene.2012.08.017

The design consideration of DU-Am oxide fuel pin was performed for Pu denaturing in the framework of the protected plutonium production based on the irradiation analyses of the depleted U (DU) samples irradiated in the environment of broad range of neutron energy in the experimental fast reactor Joyo. From the results of irradiation analyses of DU, it was confirmed that there is a strong dependence of transmutation behavior of DU on the resonance neutron ratio even in a fast reactor. Also, it was confirmed that there is a strong effect of sample material form and shape on generated Pu nuclide inventory especially near the reflector area (20% resonance neutron ratio), because of the intensive self-shielding of U, though less is expected for Am. Sensitivity study of hypothetical DU-Am oxide fuel pellet irradiation on neutron energy and burn-up was performed to evaluate significant gradient of radial Pu isotopic composition profile (e.g., from 12 to 18% distribution in 3% Am doping, in 30% resonance neutron ratio and in 4.010 [n/cm] of neutron fluence inside a large pellet with softened neutron spectrum), and vulnerability of the fuel pellet surface in terms of Pu denaturing was revealed. Design consideration of radial zoning of Am content was introduced to flatten the radial distribution of isotopic composition of Pu. The results of radial zoning of Am (4% and 3% of Am in the outer and inner zone of DU-Am oxide fuel pellet) in hypothetical irradiation neutronics analysis showed the radial profile of produced Pu is over 15 at.% of Pu isotopic composition in any zone and meets the criteria of Kimura et al. based on decay heat of Pu to impede utilization to fission explosive devices.

Microbeam irradiation facilities for radiobiology in Japan and China

Kobayashi, Yasuhiko; Funayama, Tomoo; Hamada, Nobuyuki*; Sakashita, Tetsuya; Konishi, Teruaki*; Imaseki, Hitoshi*; Yasuda, Keisuke*; Hatashita, Masanori*; Takagi, Keiichi*; Hatori, Satoshi*; et al.

Journal of Radiation Research, 50(Suppl.A), p.A29 - A47, 2009/03

https://doi.org/10.1269/jrr.09009S

Research for Am-based proliferation resistance

Shiba, Tomooki*; Sagara, Hiroshi*; Saito, Masaki*; Koyama, Shinichi; Maeda, Shigetaka

no journal, , 

In order to design for FBR blanket fuel with high proliferation resistance, transmutation behavior of Am-containing depleted uranium under fast neutron environment is evaluated by computer simulation as a parameter of the Am content. Produced plutonium having high proliferation resistance are reduced with decreasing neutron energy in the case of Joyo irradiation condition.

Blanket fuel with high proliferation resistance in fast breeder reactor, 10; Theoretical analysis of irradiated samples in JOYO, 4

Shiba, Tomooki*; Sagara, Hiroshi*; Saito, Masaki*; Onishi, Takashi; Koyama, Shinichi; Maeda, Shigetaka

no journal, , 

In order to develop blanket fuel with high proliferation resistance in fast breeder reactor, production and incineration behavior of Pu in U samples irradiated in fast experimental reactor JOYO were evaluated by calculation. Results of sample irradiation loaded at different axial position were compared and dependence of transmutation behavior on neutron energy spectra were evaluated.

Effect of ion beam irradiation to seeds on generation and growth in the seedling of capsicum native variety in Hirosaki

Maeda, Tomoo*; Tomikawa, Masaru*; Honda, Kazushige*; Saga, Koichi*; Ishikawa, Ryuji*; Akita, Yusuke; Yoshihara, Ryohei; Nozawa, Shigeki; Narumi, Issei

no journal, , 

no abstracts in English

Expression of mutations in progeny of ion-beam irradiated Capsicum native variety in Hirosaki

Sato, Yusuke*; Maeda, Tomoo*; Honda, Kazushige*; Saga, Koichi*; Ishikawa, Ryuji*; Akita, Yusuke; Nozawa, Shigeki; Hase, Yoshihiro; Narumi, Issei

no journal, , 

no abstracts in English

Characterization study of candidate technologies for nuclear material quantification in fuel debris at Fukushima Daiichi Nuclear Power Station, 1; General outline

Nagatani, Taketeru; Komeda, Masao; Shiba, Tomooki; Maeda, Makoto; Nauchi, Yasushi*; Sagara, Hiroshi*; Kureta, Masatoshi; Tomikawa, Hirofumi; Okumura, Keisuke; Heinberg, C.; et al.

no journal, , 

no abstracts in English