Analysis of the activities of the website "Question and Answer about radiation in daily life" after the accident at the Fukushima Daiichi Nuclear Power Plant and some lessons learned from it; To pass on this experience to the future

Kono, Takahiko; Tanaka, Masato*; Tanaka, Hitomi*; Shimo, Michikuni*; Torii, Hiroyuki*; Uno, Kazuko*

Journal of Radiation Protection and Research, 47(3), p.167 - 179, 2022/09

https://doi.org/10.14407/jrpr.2021.00346

After the accident at the Fukushima Daiichi Nuclear Power Plant, artificial radionuclides such as radioactive cesium and iodine were released into the environment. It caused great anxiety not only in the vicinity of the Fukushima Daiichi Nuclear Power Plant but also in other regions of the world. Some members of the Japan Health Physics Society (JHPS), a leading academic society in Japan in the field of radiation protection, volunteered to establish a website called "Question and Answer about radiation in Daily Life" shortly after the accident to help reduce the residents anxiety about the health effects of radiation. In August 2011, Committee for "Question and Answer about radiation in Daily Life" was established in JHPS, making the website-related activities a responsibility of JHPS. The Q&A website continued to respond to the questions from the general public with expertise and sincerity until February 2013 when the Committee members decided to end the activities because the number of questions received had gradually decreased with the passage of time. This paper aims to introduce the following: the activities of the Q&A website during the two years (2011-2013), the stance chosen for the activities, the information related to the website activities and the analysis of Twitter data. Building on the experience and the knowledge obtained from the activities, it also discusses issues and experiences that can be utilized in the initial response to emergencies for radiation protection experts as well as other fields.

Analysis of the activities of the website "Question and Answer about radiation in Daily Life" after the accident at the Fukushima Daiichi Nuclear Power Station and some lessons learned from it; To pass on this experience to the future

Kono, Takahiko; Shimo, Michikuni*; Hayakawa, Hironobu*; Taniguchi, Kazufumi*; Tanaka, Masato*; Tanaka, Hitomi*; Onoue, Yosuke*; Nagaya, Hiroshi*; Torii, Hiroyuki*; Uno, Kazuko*

Hoken Butsuri (Internet), 55(4), p.226 - 238, 2020/12

https://doi.org/10.5453/jhps.55.226

After the accident at the Fukushima Daiichi Nuclear Power Station, artificial radionuclides such as radioactive cesium and iodine were released into the environment. It caused great anxiety not only in the vicinity of the Fukushima Daiichi Nuclear Power Station but also in other regions of Japan. Some members of the Japan Health Physics Society (JHPS) which is a leading academic society in Japan in the field of radiation protection volunteered to establish the website called "Question and Answer about radiation in Daily Life" just after the accident to reduce the anxiety of the residents about the health effects of radiation. After that, Committee of "Question and Answer about radiation in Daily Life" was established in August 2011 in JHPS, and this activity had been carried out under the responsibility of the society that answered with sincerity against questions from the public as specialists until February 2013. The number of questions on the website had gradually decreased as time passed; therefore, the Committee members decided to end these activities in February 2013. In this paper, following contents were shown; the activities of the Q&A website for about two years, the issues of the stance on our activities, the information related to the website activities and the analysis of Twitter data. Based on the experience and the knowledge obtained from these activities, the issues and experiences that can be utilized in the initial response to emergencies for radiation protection experts as well as other fields are presented.

Determination of fusion barrier distributions from quasielastic scattering cross sections towards superheavy nuclei synthesis

Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.

Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01

https://doi.org/10.7566/JPSJ.87.014201

Excitation functions of quasielastic scattering cross sections for the Ca + Pb, Ti + Pb, and Ca + Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.

Study of fission using multi-nucleon transfer reactions

Nishio, Katsuhisa; Hirose, Kentaro; Vermeulen, M. J.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Sato, Tetsuya; Nagame, Yuichiro; et al.

EPJ Web of Conferences, 163, p.00041_1 - 00041_6, 2017/11

https://doi.org/10.1051/epjconf/201716300041

Study of the reaction Ca + Cm Lv at RIKEN-GARIS

Kaji, Daiya*; Morita, Kosuke*; Morimoto, Koji*; Haba, Hiromitsu*; Asai, Masato; Fujita, Kunihiro*; Gan, Z.*; Geissel, H.*; Hasebe, Hiroo*; Hofmann, S.*; et al.

Journal of the Physical Society of Japan, 86(3), p.034201_1 - 034201_7, 2017/03

https://doi.org/10.7566/JPSJ.86.034201

The fusion reaction of Ca + Cm Lv was studied using the gas-filled recoil-ion separator GARIS at RIKEN. A total of seven and spontaneous-fission decay chains were observed, which would originate from the reaction products of the element 116, Lv and Lv. Decay properties observed in the chains are in good agreement with the previously published ones. However, one of the chains showed a discrepancy, indicating the new spontaneous-fission branch in Cn or the production of the new isotope Lv.

Decomposition studies of group 6 hexacarbonyl complexes, 1; Production and decomposition of Mo(CO) and W(CO)

Usoltsev, I.*; Eichler, R.*; Wang, Y.*; Even, J.*; Yakushev, A.*; Haba, Hiromitsu*; Asai, Masato; Brand, H.*; Di Nitto, A.*; Dllmann, Ch. E.*; et al.

Radiochimica Acta, 104(3), p.141 - 151, 2016/03

https://doi.org/10.1515/ract-2015-2445

Conditions of the production and decomposition of hexacarbonyl complexes of short-lived Mo and W isotopes were investigated to study thermal stability of the heaviest group 6 hexacarbonyl complex Sg(CO). A tubular flow reactor was tested to decompose the hexacarbonyl complexes and to extract the first bond dissociation energies. A silver was found to be the most appropriate reaction surface to study the decomposition of the group 6 hexacarbonyl. It was found that the surface temperature at which the decomposition occurred was correlated to the first bond dissociation energy of Mo(CO) and W(CO), indicating that the first bond dissociation energy of Sg(CO) could be determined with this technique.

Production of Nb and Ta for chemical studies of element 105, Db, using the GARIS gas-jet system

Huang, M.*; Haba, Hiromitsu*; Murakami, Masashi*; Asai, Masato; Kaji, Daiya*; Kanaya, Jumpei*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Kikutani, Yuki*; Komori, Yukiko*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 304(2), p.845 - 849, 2015/05

https://doi.org/10.1007/s10967-014-3877-4

A technique to utilize radioisotopes of Nb and Ta was developed for chemical studies of element 105, Db, by coupling a gas-jet transport system to the RIKEN gas-filled recoil ion separator (GARIS). The short-lived Nb and Ta were produced with nuclear reactions using a F beam whose energy was the same as that to produce Db. Then, they were separated with GARIS and extracted to a chemistry laboratory with the gas-jet transport system. By changing only magnetic field of GARIS and inserting an energy degrader and a shutter for recoil ions, we could deliver the Nb and Ta to a chemistry device for Db without changing other experimental conditions.

Development of a new continuous dissolution apparatus with a hydrophobic membrane for superheavy element chemistry

Oe, Kazuhiro*; Attallah, M. F.*; Asai, Masato; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Huang, M.*; Kanaya, Jumpei*; Kaneya, Yusuke*; Kasamatsu, Yoshitaka*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1317 - 1320, 2015/02

https://doi.org/10.1007/s10967-014-3469-3

A new technique for continuous dissolution of nuclear reaction products transported by a gas-jet system was developed for superheavy element (SHE) chemistry. In this technique, a hydrophobic membrane is utilized to separate an aqueous phase from the gas phase. With this technique, the dissolution efficiencies of short-lived radionuclides of Mo and W were measured. Yields of more than 80% were observed for short-lived radionuclides at aqueous-phase flow rates of 0.1-0.4 mL/s. The gas flow-rate had no influence on the dissolution efficiency within the studied flow range of 1.0-2.0 L/min. These results show that this technique is applicable for on-line chemical studies of SHEs in the liquid phase.

Source development and novel applications of laser-driven plasma X-ray lasers in JAEA

Kawachi, Tetsuya; Hasegawa, Noboru; Nishikino, Masaharu; Ishino, Masahiko; Imazono, Takashi; Oba, Toshiyuki; Kaihori, Takeshi; Kishimoto, Maki; Ochi, Yoshihiro; Tanaka, Momoko; et al.

X-Ray Lasers 2010; Springer Proceedings in Physics, Vol.136, p.15 - 24, 2011/12

http://ci.nii.ac.jp/ncid/BB05543208

This paper reviews recent improvement in the source development of laser-driven X-ray lasers and the applications in the research fields of material science, laser processing, X-ray imaging, and radiation damage in biological cells. In the application for material science, we have firstly observed temporal correlation between the domain structures of ferro-electric substance under the Curie temperature. In the laser processing, new X-ray laser interferometer reveals us the nano-scale surface distortion of substance pumped by a femto-second optical pulse. In the X-ray diffraction image, we have taken several static images of micro-structure of samples: now we are trying to extend the objective to nano-scale dynamics using pump and probe method. In the radiation damage of biological cells, we observed double strand break in DNA using X-ray laser exposure; this results are compared with the case using incoherent several KeV X-ray exposure.

Generation of above 10 temporal contrast, above 10W/cm peak intensity pulses at a 10 Hz repetition rate using an OPCPA preamplifier in a double CPA, Ti:sapphire laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; Kanazawa, Shuhei; Sagisaka, Akito; Daito, Izuru; et al.

AIP Conference Proceedings 1153, p.3 - 6, 2009/07

https://doi.org/10.1063/1.3204551

We demonstrate a high-contrast, high-intensity double chirped-pulse amplification (CPA) Ti:sapphire laser system using an optical parametric chirped-pulse amplifier (OPCPA) as a preamplifier. By injecting cleaned microjoule seed pulses into the OPCPA, a temporal contrast greater than 10 within picosecond times before the main femtosecond pulse is demonstrated with the output pulse energy of 1.7 J and pulse duration of 30 fs, corresponding to a peak power of 60 TW at a 10 Hz repetition rate. This system uses a cryogenically-cooled Ti:sapphire final amplifier and generates focused peak intensities in excess of 10 W/cm.