カク ホウシャ カガク ノ ショウカイ : ジュウゲンソ カガク カラ カンキョウ ホウシャノウ ムキ ブンセキ カガク イヨウ キキ カイハツ マデ

The end of the late１９th century, nuclear and radiochemistry was firstly constructed by one of great chemists, Marie Curie. At that time, she had carried out the first discovery of two new elements, polonium and radium, using chemical decomposition and separation methods of the first exercise in radiochemistry of uranium ores. Currently, nuclear and radiochemistry plays an important role in various fundamental and applied research fields from physics, chemistry, and biology, toward the environment, energy, industrial materials, life science, medicine, agriculture, education, and so on. This review is focused mainly on the introduction of current nuclear and radiochemistry, in particular, from the nuclear sciences of transuranium nuclides including recent experimental works of superheavy element chemistry toward radioactivity in the environment, inorganic analytical chemistry and the application of scientific technology to development of medical device

Recent great impact by an Isotope Separator On-Line(ISOL) in nuclear and radiochemistry

On April 9 2015, the Letter article titled “Measurement of the first ionization potential of lawrencium, element 103” is now published at News and Views on Nature (2015) which has been performed by our remarkably Japanese colleagues of nuclear and radiochemistry at JAEA (Japan Atomic Energy Agency). In this review, the author will state that the isotope separator on-line (ISOL) our regularly used, one of mass separation techniques, with a thermal surface ionization makes possible for determining the ionization potential of lawrencium based on the fruitful fundations of developing the ISOL system until now and also ever studying searches for unknown nuclei and these nuclear decay properties around actinide region in the past 20 years

Knowledge and risk perception of radiation for Japanese nursing students after the Fukushima Nuclear Power Plant disaster

Background: The Japanese have had three experiences of radiation disasters: the atomic bombs dropped on Hiroshima and Nagasaki in 1945, and the 2011 Fukushima Nuclear Power Plant disaster. The former two experiences have been covered in compulsory education programs. In light of these incidents, a strong fear of radiation has pervaded people of several generations. In such a situation, the role of nurses is important. When nurses treat residents, their attitudes change depending on how they understand and feel about radiation. The foundations of these attitudes are formed through student education. Hence, it is necessary to explore nursing students' understanding and risk perception of radiation, and the nature of radiation education received. Objectives: To assess the levels of understanding and risk perception of nursing students regarding radiation. Design: Cross-sectional survey. Methods: A questionnaire survey was administered to all students (74 first-year, 79 second-year, 65 third-year, and 69 fourth-year students) in the nursing department of a Japanese national university. The response rate was 84%. Respondents were asked to rate their level of understanding of 50 phrases chosen from two supplementary texts about radiation for elementary school students and for middle and high school students, prepared by the Japanese Ministry. Further, they were asked to rate their risk perception for 30 events, and to answer six questions about radiation. Results: It was found that knowledge about radiation among Japanese nursing students was poor, because sufficient radiation education had not been provided. Hence, they displayed a greater fear of X-rays as compared to American students and members of the League of Woman Voters. However, it was also found that an increase in understanding might decrease risk perception. Conclusions: It was concluded that nursing students require adequate education about radiation, in order to reduce their fear of X-rays and to mitigate their risk perception

ソウコウ サーベイ ニヨル カガワケン ノ カンキョウ ホウシャセン チョウサ

After the accident of the Fukushima Daiichi nuclear power plant by the Great East Japan Earthquake on March 11, 2011, concern about radiation is increasing and monitoring of environmental radiation is performed even in Kagawa Prefecture. Then, we investigated for a short period of time for the purpose of creating the dose rate distribution map of Kagawa Prefecture while getting to know the dose rate of each municipality in Kagawa Prefecture in detail using a car-borne survey technique. As a result of measurement, the dose rates were low in the plain regions and those became high in the mountainous regions. Due to the average value of each municipality, the dose rates of municipalities in the southeastern prefecture, which contain Izumi Group and mountainous region affluent in granite, were high. The average dose rates of all municipalities in Kagawa Prefecture were obtained from this investigation, and the dose rate distribution map was created. From the tendency of the dose rate distribution in Kagawa, it has confirmed that a dose rate changed with geographical feature or geology

A Car-borne Survey of Environmental Radiation in Shikoku, Japan

We investigated the environmental radiation in Shikoku area using a car-borne survey and obtained the change of dose rate by continuous survey. Dose rartes in Ozu city and its surrounding area, Ehime prefecture were the lowest in other areas of Shikoku. Dose rates obviously changed on the north side of it’s low dose rates area but gradually changed on the south side. Dose rates in Ashizuri-misaki, Kochi prefecture were the highest in Shikoku and changed in accordance with the boundary of geological structure. Dose rate on the survey route, from Imabari city in Ehime prefecture to Shimanto city in Kochi prefecture, was the lowest at the surrounding area of the prefectural boundary. This lowest dose rate was considered to be caused by geological structure. The influence of altitued on dose rates was not observed in this survey route.The average dose rates of environmental radiation in Ehime prefecture and Kochi prefecture were almost the same and the lowest in Shikoku. Tokushima prefecture was the highest in the average dose rates of environmental radiation of other prefectures in Shikoku

トクシマ ニオケル フクシマ ダイイチ ゲンシリョク ハツデンショ ジコ ニ トモナウ タイキチュウ ジンコウ ホウシャセイ カクシュ ノ ソクテイ

The airborne radioactive isotopes from the Fukushima Daiichi nuclear plant was measured in Tokushima, western Japan. The continuous monitoring has been carries out in Tokushima, Japan. From March 23, 2011 the fission product 131I was observed. The radioisotopes 134Cs and 137Cs were also observed in the beginning of April. However the densities were extremely smaller than the Japanese regulation of radioisotopes

Availability of Japanese Government's supplemental texts on radiation reflecting the Fukushima Daiichi Nuclear Power Plant accident for elementary and secondary education from dental students' understanding

Following the Fukushima Nuclear Power Plant accident, the Japanese government created two supplemental texts about radiation reflecting the accident for elementary, middle school, and high school students. These texts were made to explain radiation and consequently to obtain public consent for the continuation of the nuclear program. The present study aimed to evaluate the appropriateness of the content of the texts and to collect the basic data on the level of understanding necessary to improve radiation education. Lectures on radiology including nuclear energy and the Fukushima accident were given to 44 fourth-year dental students in 2013. The questionnaire was administered in 2014 when these students were in their sixth-year. The survey was also administered to 40 first-year students and 41 fourth-year students who hadn't any radiology lectures. Students rated their level of understanding of 50 phrases used in the texts on a four-point scale (understanding = 3, a little knowledge = 2, having heard = 1, no knowledge = 0). Questions on taking an advanced physics course in high school and means of learning about radiation in daily life were also asked. The level of understanding of phrases in the supplemental text for middle and high school students was significantly higher among sixth-year students (mean = 1.43) than among first-year (mean = 1.12) or fourth-year (mean = 0.93) students (p < 0.05). Overall, the level of understanding was low, with scores indicating that most students knew only a little. First-year students learning about radiation from television but four-year and six-year students learning about radiation from newspaper scored significantly higher (p < 0.05). It was concluded that radiation education should be improved by using visual material and preparing educators to teach the material for improving the public's understanding of radiation use—especially nuclear power generation because the phrases used in the supplementary texts are very difficult for students to understand

Thermal neutron flux evaluation by a single crystal CVD diamond detector in LHD deuterium experiment

The single crystal CVD diamond detector (SDD) was installed in the torus hall of the Large Helical Device (LHD) to measure neutrons with high time resolution and neutron energy resolution. The LiF foil with 95.62 % of 6Li isotope enrichment pasted on the detector was used as the thermal neutron convertor as the energetic ions of 2.0 MeV alpha and 2.7 MeV triton particles generated in LiF foil and deposited the energy into SDD. SDD were exposed to the neutron field in the torus hall of the LHD during the 2nd campaign of the deuterium experiment. The total pulse height in SDD was linearly propotional to the neutron yield in a plasma operation in LHD over 4 orders of magnitude. The energetic alpha and triton were separately measured by SDD with LiF with the thickness of 1.9 μm, although SDD with LiF with the thickness of 350 μm showed a broadened peak due to the large energy loss of energetic particles generated in the bulk of LiF. The modeling with MCNP and PHITS codes well interpreted the pulse height spectra for SDD with LiF with different thicknesses. The results above demonstrated the sufficient time resolution and energy discrimination of SDD used in this work

FEASIBILITY STUDY ON THE FUSION OF PHITS SIMULATIONS AND THE DLNN ALGORITHM

We have recently have developed an in-situ multiple-channel depth distribution spectrometer (DDS) that can easily acquire on-site measurements of the depth distribution of specific radioactivities of Cs-134 and Cs-137 underground. Despite considerable improvements in the hardware developed for this device, the quantitative method for determining of radioactivities with this DDS device cannot yet achieve satisfactory performance for practical use. For example, this method cannot discriminate each γ-ray spectra of Cs-134 and Cs-137 acquired by the 20 thallium-doped caesium iodine CsI(Tl) scintillation crystal detectors of the DDS device from corresponding depth levels of underground soil. Therefore, we have applied deep learning neural network (DLNN) as a novel radiation measurement technique to discriminate the spectra and to determine the specific radioactivities of Cs-134 and Cs-137. We have developed model soil layers on a virtual space in Monte-Carlo based PHITS simulations and transported γ-ray radiation generated from a particular single soil layer or multiple layers as radiation sources; next, we performed PHITS calculations of those specific radioactivity measurements for each soil layer using DDS device based on machine learning via the DLNN algorithm. In this study, we obtained informative results regarding the feasibility of the proposal innovative radiation measurement method for further practical use in on-site applications

Chemical Characterization of a Volatile Dubnium Compound, DbOCl3

The formation and the chemical characterization of single atoms of dubnium (Db, element 105), in the form of its volatile oxychloride, was investigated using the on-line gas phase chromatography technique, in the temperature range 350–600 °C. Under the exactly same chemical conditions, comparative studies with the lighter homologues of Group 5 in the Periodic Table clearly indicate the volatility sequence being NbOCl3 > TaOCl3 ≥ DbOCl3. From the obtained experimental results, thermochemical data for DbOCl3 were derived. The present study delivers reliable experimental information for theoretical calculations on chemical properties of transactinides