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JAEA Reports

Data comparison of measurement of carbon isotope standards between JAEA-AMS-TONO and JAEA-AMS-MUTSU

Kokubu, Yoko; Matsubara, Akihiro; Fujita, Natsuko; Kuwabara, Jun; Kinoshita, Naoki

JAEA-Technology 2021-028, 33 Pages, 2022/02

JAEA-Technology-2021-028.pdf:2.18MB

Japan Atomic Energy Agency (JAEA) has two facilities of accelerator mass spectrometry, JAEA-AMS-TONO and JAEA-AMS-MUTSU at Tono Geoscience Center and Aomori Research and Development Center, respectively. In this report, characteristics of each facility and results of standard samples in the inner-comparison test of carbon isotope measurement will be described. Both facilities have been used for research by not only JAEA's staff but also researchers who belong to universities and other institutes on the shared use program of JAEA facilities. Recently, researchers trend to use both facilities with the expansion of demand for the carbon isotope measurement by using the accelerator mass spectrometer (AMS). However, each facility has a spectrometer made by a different manufacturer and equipped with different mechanical components. There is a difference in each ability to the carbon isotope measurement such as background level. This is, for example, due to different ion injection system adapted at each spectrometer. Further, each facility uses a different analytical method adjusted to each main research field. When a researcher uses both facilities, the researcher understands more about the characteristics and need to make a suitable choice of a facility for samples and the analytical method. The report presents a detailed information of characteristics of the spectrometer, sample preparation method and analytical method, and of ability of the measurement based on the inner-comparison test.

Journal Articles

A Model intercomparison of atmospheric $^{137}$ Cs concentrations from the Fukushima Daiichi Nuclear Power Plant accident, phase III; Simulation with an identical source term and meteorological field at 1-km resolution

Sato, Yosuke*; Sekiyama, Tsuyoshi*; Fang, S.*; Kajino, Mizuo*; Qurel, A.*; Qulo, D.*; Kondo, Hiroaki*; Terada, Hiroaki; Kadowaki, Masanao; Takigawa, Masayuki*; et al.

Atmospheric Environment; X (Internet), 7, p.100086_1 - 100086_12, 2020/10

https://doi.org/10.1016/j.aeaoa.2020.100086

The third model intercomparison project for investigating the atmospheric behavior of $^{137}$ Cs emitted during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident (FDNPP-MIP) was conducted. A finer horizontal grid spacing (1 km) was used than in the previous FDNPP-MIP. Nine of the models used in the previous FDNPP-MIP were also used, and all models used identical source terms and meteorological fields. Our analyses indicated that most of the observed high atmospheric $^{137}$ Cs concentrations were well simulated, and the good performance of some models improved the performance of the multi-model ensemble. The analyses also confirmed that the use of a finer grid resolution resulted in the meteorological field near FDNPP being better reproduced. The good representation of the wind field resulted in the reasonable simulation of the narrow distribution of high deposition amount to the northwest of FDNPP and the reduction of the overestimation over the area to the south of FDNPP. In contrast, the performance of the models in simulating plumes observed over the Nakadori area, the northern part of Gunma, and the Tokyo metropolitan area was slightly worse.

Journal Articles

Guidance for gamma spectrometry intercomparison based on the information obtained through five intercomparisons during the Fukushima mapping project

Mikami, Satoshi; Ishikawa, Daisuke*; Matsuda, Hideo*; Hoshide, Yoshifumi*; Okuda, Naotoshi*; Sakamoto, Ryuichi*; Saito, Kimiaki

Journal of Environmental Radioactivity, 210, p.105938_1 - 105938_7, 2019/12

https://doi.org/10.1016/j.jenvrad.2019.03.014

Times Cited Count：2 Percentile：8.42(Environmental Sciences)

Five intercomparisons of in situ spectrometry by 6-7 participating teams have been conducted between December 2011 and August 2015 at sites in Fukushima prefecture which affected by the fallout of FDNPS accident occurred in March 2011. The evaluated deposition densities agreed within 5-6% in terms of coefficient of variation (CV) for radiocesium ( $^{134}$ Cs and $^{137}$ Cs), by our best achievement, and the ratio of $^{134}$ Cs/ $^{137}$ Cs in deposition density agreed within 1-2% in CV, through five intercomparisons. These results guarantee the accuracy of the measurements of the mapping project. Two different methods for intercomparison were conducted: (1) sequential measurements at an identical point; and (2) simultaneous measurements in a narrow area within 3 m radius. In a comparison between the two methods at a site, no significant difference was observed between the results. The standard protocols for the two different intercomparison methods were proposed based on our experience.

Journal Articles

Intercomparison of numerical atmospheric dispersion prediction models for emergency response to emissions of radionuclides with limited source information in the Fukushima Dai-ichi Nuclear Power Plant accident

Iwasaki, Toshiki*; Sekiyama, Tsuyoshi*; Nakajima, Teruyuki*; Watanabe, Akira*; Suzuki, Yasushi*; Kondo, Hiroaki*; Morino, Yu*; Terada, Hiroaki; Nagai, Haruyasu; Takigawa, Masayuki*; et al.

Atmospheric Environment, 214, p.116830_1 - 116830_11, 2019/10

https://doi.org/10.1016/j.atmosenv.2019.116830

Times Cited Count：6 Percentile：26.43(Environmental Sciences)

The utilization of numerical atmospheric dispersion prediction (NDP) models for accidental discharge of radioactive substances was recommended by a working group of the Meteorological Society of Japan. This paper is to validate the recommendation through NDP model intercomparison in the accidental release from the Fukushima Dai-ichi Nuclear Power Plant in 2011. Emission intensity is assumed to be constant during the whole forecast period for the worst-case scenario unless time sequence of emission is available. We expect to utilize forecasts of surface air contaminations for preventions of inhalations of radioactive substances, and column-integrated amounts for mitigation of radiation exposure associated with wet deposition. Although NDP forecasts have ensemble spread, they commonly figure out relative risk in space and time. They are of great benefit to disseminating effective warnings to public without failure. The multi-model ensemble technique may be effective to improve the reliability.

Journal Articles

Model intercomparison of atmospheric $^{137}$ Cs from the Fukushima Daiichi Nuclear Power Plant accident; Simulations based on identical input data

Sato, Yosuke*; Takigawa, Masayuki*; Sekiyama, Tsuyoshi*; Kajino, Mizuo*; Terada, Hiroaki; Nagai, Haruyasu; Kondo, Hiroaki*; Uchida, Junya*; Goto, Daisuke*; Qulo, D.*; et al.

Journal of Geophysical Research; Atmospheres, 123(20), p.11748 - 11765, 2018/10

https://doi.org/10.1029/2018JD029144

Times Cited Count：40 Percentile：85.28(Meteorology & Atmospheric Sciences)

A model intercomparison of the atmospheric dispersion of $^{137}$ Cs emitted following the Fukushima Daiichi Nuclear Power Plant accident was conducted by 12 models to understand the behavior of $^{137}$ Cs in the atmosphere. The same meteorological data, horizontal grid resolution, and an emission inventory were applied to all the models to focus on the model variability originating from the processes included in each model. The multi-model ensemble captured 40% of the observed $^{137}$ Cs events, and the figure-of-merit in space for the total deposition of $^{137}$ Cs exceeded 80. Our analyses indicated that the meteorological data were most critical for reproducing the $^{137}$ Cs events. The results also revealed that the differences among the models were originated from the deposition and diffusion processes when the meteorological field was simulated well. However, the models with strong diffusion tended to overestimate the $^{137}$ Cs concentrations.

Journal Articles

Atmospheric modeling of $^{137}$ Cs plumes from the Fukushima Daiichi Nuclear Power Plant; Evaluation of the model intercomparison data of the Science Council of Japan

Kitayama, Kyo*; Morino, Yu*; Takigawa, Masayuki*; Nakajima, Teruyuki*; Hayami, Hiroshi*; Nagai, Haruyasu; Terada, Hiroaki; Saito, Kazuo*; Shimbori, Toshiki*; Kajino, Mizuo*; et al.

Journal of Geophysical Research; Atmospheres, 123(14), p.7754 - 7770, 2018/07

https://doi.org/10.1029/2017JD028230

Times Cited Count：24 Percentile：69.81(Meteorology & Atmospheric Sciences)

We compared seven atmospheric transport model results for $^{137}$ Cs released during the Fukushima Daiichi Nuclear Power Plant accident. All the results had been submitted for a model intercomparison project of the Science Council of Japan in 2014. We assessed model performance by comparing model results with observed hourly atmospheric concentrations of $^{137}$ Cs, focusing on nine plumes over the Tohoku and Kanto regions. The results showed that model performance for $^{137}$ Cs concentrations was highly variable among models and plumes. We also assessed model performance for accumulated $^{137}$ Cs deposition. Simulated areas of high deposition were consistent with the plume pathways, though the models that best simulated $^{137}$ Cs concentrations were different from those that best simulated deposition. The ensemble mean of all models consistently reproduced $^{137}$ Cs concentrations and deposition well, suggesting that use of a multimodel ensemble results in more effective and consistent model performance.

Journal Articles

In situ spectrometry intercomparison in Fukushima, Japan

Mikami, Satoshi; Sato, Shoji*; Hoshide, Yoshifumi*; Sakamoto, Ryuichi*; Okuda, Naotoshi*; Saito, Kimiaki

Hoken Butsuri, 50(3), p.182 - 188, 2015/09

https://doi.org/10.5453/jhps.50.182

Intercomparison of in situ spectrometry was organized at a site contaminated by the radioactive fallout that originated from the Fukushima Dai-ichi Nuclear Power Plant accident. This intercomparison was conducted by eight teams from four different institutions, which have contributed to the government-led project to construct distribution maps of radionuclides deposited on the ground soil. The resultant $^{134}$ Cs and $^{137}$ Cs inventories evaluated by the participants agreed within 6% of the coefficient of variation, after correction for inhomogeneous distribution of the air dose rate. The evaluated $^{40}$ K inventories agreed within 4% of the coefficient of variation. The authors estimated that these results were in good agreement for creating distribution maps of the radionuclide inventory in the ground soil.

Journal Articles

Inter-code comparison of TRIPOLI and MVP on the MCNP criticality validation suite

Brun, E.*; Zoia, A.*; Trama, J. C.*; Lahaye, S.*; Nagaya, Yasunobu

Proceedings of International Conference on Nuclear Criticality Safety (ICNC 2015) (DVD-ROM), p.351 - 360, 2015/09

This paper presents a joint work conducted at CEA Saclay and JAEA Tokai aimed at comparing the Monte Carlo codes TRIPOLI and MVP on a selection of ICSBEP benchmarks. Our goal is to establish a common set of Monte Carlo input decks, as a basis for rigorous inter-code comparison in criticality-safety. As a reference, we will use the MCNP Criticality Validation Suite: other Monte Carlo developers might easily join that effort in the future. For the purpose of inter-code comparison, the TRIPOLI and MVP input decks have been translated from those of MCNP, without any further assumptions. Both TRIPOLI and MVP have been run with the same ENDF/B-VII.0 evaluated nuclear data, and as far as possible the same simulation options as in the original LANL work. In this abstract, we present preliminary results on the BIGTEN benchmark. In the full paper these will be extended to the 31 benchmarks of the MCNP Criticality Validation Suite. In the future, this database will also help in the analysis of sensitivity to nuclear data, CPU times and figures of merit.

Journal Articles

Comparison of JSFR design with EDF requirements for future SFR

Uematsu, Mari Mariannu; Prle, G.*; Mariteau, P.*; Sauvage, J.-F.*; Hayafune, Hiroki; Chikazawa, Yoshitaka

Journal of Nuclear Science and Technology, 52(3), p.434 - 447, 2015/03

https://doi.org/10.1080/00223131.2014.953015

Times Cited Count：1 Percentile：9.74(Nuclear Science & Technology)

Electricite de France (EDF) and JAEA have signed a bilateral agreement for research and development cooperation and information exchange on future sodium-cooled fast reactors (SFR) since 2008. Within the bilateral framework, a comparison of Japan sodium-cooled fast reactor (JSFR) design with future French SFR concept has been done based on, firstly the requirement of the investor operator (EDF) of future French SFRs and secondly the French safety baseline that could be applicable to these reactors which is currently under preparation. This paper describes the comparison work results of JSFR and EDF requirements for future SFRs where the specific designs of JSFR were evaluated as interesting from EDF point of view. The comparison work pointed out the differences in safety baselines between two countries as well.

Journal Articles

RCA/IAEA third external dosimetry intercomparisons in East Asia region

Yamamoto, Hideaki; Yoshizawa, Michio; Murakami, Hiroyuki; Momose, Takumaro*; Tsujimura, Norio*; Kanai, Katsuta*; Cruz-Suarez, R.*

Radiation Protection Dosimetry, 125(1-4), p.88 - 92, 2007/07

https://doi.org/10.1093/rpd/ncl539

Times Cited Count：0 Percentile：0.01(Environmental Sciences)

The purpose of this paper is to discuss the results of the third intercomparison exercise of external radiation dosimetry organized under the Regional Cooperative Agreement (RCA) in the East Asia region of the International Atomic Energy Agency (IAEA). Twenty five laboratories from 16 member states participated in the exercise. Japan Atomic Energy Research Institute (JAERI) and Japan Nuclear Cycle Development Institute (JNC) arranged the standard irradiation of the participants' dosimeters. The results of the measurements of the irradiated dosimeters for the determination of external doses were satisfactory for all participants, demonstrating good performance in their external dosimetry.

Journal Articles

Applicability study on existing dosimetry systems to high-power Bremsstrahlung irradiation

Mehta, K.*; Kojima, Takuji; Sunaga, Hiromi

Radiation Physics and Chemistry, 68(6), p.959 - 962, 2003/12

https://doi.org/10.1016/j.radphyschem.2003.08.007

Times Cited Count：3 Percentile：25.79(Chemistry, Physical)

Applicability of the existing dosimetry systems to high-power Bremsstrahlung irradiation was investigated through a dose intercomparison study, where several dosimeters were irradiated in the dose range 4-12 kGy in identical polyethylene phantoms in a Bremsstrahlung beam obtained from a 5-MeV electron accelerator. Included in the study were alanine dosimeters molded by three different binders, three types of liquid dosimeters:ceric-cerous, dichromate and ethanol-chlorobenzen (ECB), and glutamine powder. The dosimeter responses for Bremsstrahlung radiation were analyzed at the issuing laboratories, and the dose values determined using calibration based on cobalt-60 -ray irradiation. Dose values for all the three dose levels for all dosimetry systems were in good agreement of better than 3%. The results of the study demonstrate that these existing dosimetry systems have a potential for application to high-power Bremsstrahlung irradiation.

JAEA Reports

Uncertainty analyses for HLW disposal system using probabilistic safety assessment code (GSRW-PSA); Parameter uncertainty and conceptual model uncertainty in natural barrier

Takeda, Seiji; Kimura, Hideo

JAERI-Research 2002-014, 20 Pages, 2002/07

JAERI-Research-2002-014.pdf:1.37MB

no abstracts in English

JAEA Reports

Comparison of (n,2n) and (n,3n) reaction cross sections for fission products in JENDL-3.2 with available experimental and other evaluated cross section data

Manokhin, V. N.*; Odano, Naoteru; Hasegawa, Akira

JAERI-Data/Code 2001-019, 169 Pages, 2001/07

JAERI-Data-Code-2001-019.pdf:5.26MB

Results of comparison of (n,2n) and (n,3n) reaction cross sections for 155 nuclei (Ge - Tb) in JENDL-3.2 with available experimental data, various evaluated data, and those estimated from systematics are summarized to assess validity of cross sections for threshold reactions for fission product nuclei in JENDL-3.2. Plots for comparisons are compiled and issues in cross section data in JENDL-3.2 are also discussed.

JAEA Reports