Repeatability and reproducibility of measurements of low dissolved radiocesium concentrations in freshwater using different pre-concentration methods

Kurihara, Momo*; Yasutaka, Tetsuo*; Aono, Tatsuo*; Ashikawa, Nobuo*; Ebina, Hiroyuki*; Iijima, Takeshi*; Ishimaru, Kei*; Kanai, Ramon*; Karube, Jinichi*; Konnai, Yae*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 322(2), p.477 - 485, 2019/11

https://doi.org/10.1007/s10967-019-06696-2

We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the Cs results were within 2, indicating that the methods were accurate. The relative standard deviations (RSDs) indicating the variability in the results from different laboratories were larger than the RSDs indicating the variability in the results from each separate laboratory.

Study on current US views on bilateral civilian nuclear cooperation agreements

Tazaki, Makiko; Tamai, Hiroshi; Shimizu, Ryo; Kimura, Takashi; Kitade, Yuta; Nakanishi, Hiroaki; Suda, Kazunori

Nihon Kaku Busshitsu Kanri Gakkai Dai-39-Kai Nenji Taikai Rombunshu (Internet), 7 Pages, 2018/11

no abstracts in English

Summary of research result of State Level Concept (SLC)

Kimura, Takashi; Tazaki, Makiko; Kitade, Yuta; Shimizu, Ryo; Tamai, Hiroshi; Nakanishi, Hiroaki; Suda, Kazunori

Nihon Kaku Busshitsu Kanri Gakkai Dai-39-Kai Nenji Taikai Rombunshu (Internet), 5 Pages, 2018/11

This is the summary of research result of State Level Concept (SLC) which has been developed and conducted by the IAEA and a major purpose of the research reported here is to promote the nuclear operator's understandings for the importance of Broder Conclusion drawn continuously by the IAEA under SLC.

Relationships between sediment concentrations from Be analysis and morphometric aspect in Sangun catchment Area, Fukuoka Prefecture, Japan

Pachri, H.*; Mitani, Yasuhiro*; Ikemi, Hiroaki*; Nakanishi, Ryunosuke*; Kokubu, Yoko

Journal of Geological Resource and Engineering, 3(4), p.163 - 172, 2015/09

https://doi.org/10.17265/2328-2193/2015.04.001

Recently, the contributions of slope failures have been difficult to quantify over the time scales of the sediment concentrations in Sangun catchment area, Fukuoka Prefecture. This paper describes how cosmogenic nuclide methods have provided information about the geomorphic process by utilizing Be. The Be/Be ratios were measured by AMS. We assume that the cosmogenic nuclide concentrations stored in the sediment of a river can increase or decrease, depending on the amount of mixing of sediments during transport through the fluvial system. As results, the Be concentrations have been calculated to determine the short term sediment mixing rate in the catchment area. Therefore, the relationship between the morphometrics of the drainage basin, the sediment concentration by Be analysis and the contribution of landslides to landscape changes over timescales of several years have been investigated in Sangun catchment area.

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Transparency of peaceful use in nuclear fuel cycle

Tamai, Hiroshi; Tazaki, Makiko; Kitade, Yuta; Shimizu, Ryo; Kimura, Takashi; Nakanishi, Hiroaki; Suda, Kazunori

no journal, , 

Since the early stage of its peaceful nuclear use, Japan has promoted the plutonium management with transparent manner as a main stream of the nuclear fuel cycle policy. This paper briefly reviews good practices of plutonium management transparency and the current trend of plutonium policies in leading countries.

A Study to define and categorize the essential elements for the denuclearization

Nakanishi, Hiroaki

no journal, , 

This paper investigates the essential elements derived from a case study that examined denuclearization carried out in the past in several countries like South Africa, to clearly explain the actual definition of denuclearization. Specifically, the case study was based on a research conducted by examining denuclearization-related official documents such as agreements, protocols, declarations, statements, national laws, and concluded resolutions and reports which were enacted and published by the respective Governments and international organizations. As a result of this activity, the relevant essential elements were defined and categorized. Through this study, measures to physically remove nuclear weapons and programs from these countries were defined and categorized into the following two elements: firstly, the disablement, dismantling, disposal, removal, freezing of nuclear weapons, programs, and activities; and secondly, the assurance to prohibit nuclear explosive tests. In addition, in terms of scientific and technical aspects of the denuclearization process, it also identified that the prohibition of the re-acquisition of nuclear weapons and programs could be a third essential element of denuclearization. Lastly, this study recommended measures to address concerns for the scientists, engineers, technical staffs who were involved in the country's nuclear weapons program, and the country's know-how on the manufacturing of nuclear weapons, including illegal procurement routes of nuclear weapon-related components. The following necessary actions are recommended: first, the measures preventing such technology outflow (e.g. re-employment of relevant individuals and export control); second, the application and implementation of the IAEA safeguards; third, the capacity-building support activities for the implementation of IAEA safeguards and strengthening the country's nuclear security; and fourth, the establishment of a nuclear-weapon-free zone in the region.

The Development of laser-driven epithermal neutron source for resonance spectral diagnostics, 2

Lan, Z.*; Yogo, Akifumi*; Mirfayzi, S. R.*; Koizumi, Mitsuo; Hayakawa, Takehito*; Arikawa, Yasunobu*; Abe, Yuki*; Golovin, D.*; Mori, Takato*; Wei, T.*; et al.

no journal, , 

Evaluation of labile Cs in Fukushima rivers by diffusive gradients in thin films (DGT), 3; Relations between geochemical parameters

Tanaka, Takuro*; Saito, Takumi*; Toda, Kanako*; Fujiwara, Kenso; Terashima, Motoki; Nakanishi, Takahiro; Kobayashi, Natsuko*; Tanoi, Keitaro*; Kato, Hiroaki*

no journal, , 

Cs dispersed by the Fukushima Daiichi Nuclear Power Plant accident deposited in Fukushima area, that are not decontaminated in mountainous areas, may migrate through river water to animals and plants. Most of Cs in river are fixed in clay minerals, but there are some Cs that can be easily desorbed, named as labile components. It has been suggested that labile components affect the bioavailability of Cs. In this study, the labile Cs was sampled in situ from upstream to downstream in several rivers of Fukushima using a passive sampler called diffusive gradients in thin films (DGT). The desorption behavior of the labile component and factors affecting it will be discussed by examining the relationship with particulate Cs and geochemical parameters in river water.

Estimation of Cs-137 transport flux by shallow groundwater discharge from forested hillslope

Niwano, Yuma*; Kato, Hiroaki*; Onda, Yuichi*; Sato, Hikaru*; Iida, Hikaru*; Anderson, D.*; Nakanishi, Miyu*; Niizato, Tadafumi

no journal, , 

no abstracts in English