Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Maurer, C.*; Galmarini, S.*; Solazzo, E.*; Ku
mierczyk-Michulec, J.*; Bar
, J.*; Kalinowski, M.*; Schoeppner, M.*; Bourgouin, P.*; Crawford, A.*; Stein, A.*; et al.
Journal of Environmental Radioactivity, 255, p.106968_1 - 106968_27, 2022/12
Times Cited Count：9 Percentile：41.04(Environmental Sciences)After performing multi-model exercises in 2015 and 2016, a comprehensive Xe-133 atmospheric transport modeling challenge was organized in 2019. For evaluation measured samples for the same time frame were gathered from four International Monitoring System stations located in Europe and North America with overall considerable influence of IRE and/or CNL emissions. As a lesion learnt from the 2nd ATM-Challenge participants were prompted to work with controlled and harmonized model set ups to make runs more comparable, but also to increase diversity. Effects of transport errors, not properly characterized remaining emitters and long IMS sampling times (12 to 24 hours) undoubtedly interfere with the effect of high-quality IRE and CNL stack data. An ensemble based on a few arbitrary submissions is good enough to forecast the Xe-133 background at the stations investigated. The effective ensemble size is below five.
Maurer, C.*; Bar, J.*; Kusmierczyk-Michulec, J.*; Crawford, A.*; Eslinger, P. W.*; Seibert, P.*; Orr, B.*; Philipp, A.*; Ross, O.*; Generoso, S.*; et al.
Journal of Environmental Radioactivity, 192, p.667 - 686, 2018/12
Times Cited Count：33 Percentile：65.92(Environmental Sciences)It is very important to understand the impact for CTBT stations caused by radioxenon emitted from medical isotope production facilities for detection of underground nuclear tests. Predictions of the impact on six CTBT radionuclide stations in the Southern Hemisphere of radioxenon emitted from the medical isotope production facility in Australia were carried out by participants from ten nations using ATM (Atmospheric Transport Modeling) based on the emission data of radioxenon from this facility, as part of study on impact of radioxenon emitted from medical isotope production facilities on CTBT radionuclide stations.
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
JAEA-Technology 2017-028, 33 Pages, 2018/01
JAEA-Technology-2017-028.pdf:38.85MB
The International Noble Gas Experiment related to monitoring network for radioactive noble gas (xenon) has been carried out all over the world, as part of the International Monitoring System (IMS) of CTBT. Thirty IMS radionuclide stations including the Takasaki station in Japan are monitoring radioxenon. The past measurement results show that several stations often detect radioxenon and the major emission source of these radioxenon is medical radioisotope production facilities. And nuclear power plants and medical institutions used radioxenon for nuclear medicine diagnosis, and so on are also considered as the possible sources of radioxenon, and it is therefore important to understand the background behavior of radioxenon originated from above facilities for enhancement of monitoring capability for nuclear tests. The international joint measurement was conducted in 2012 by the Preparatory Commission for the CTBT Organization, US Pacific Northwest National Laboratory, Japan Chemical Analysis Center and JAEA at the Ohminato site of JAEA Aomori Research and Development Center in Mutsu city, Aomori, as part of investigation on radioxenon background in East Asia region. In 2014, the additional measurement was carried out at the same place for further investigation. A high sensitive Transportable Xenon Laboratory developed by PNNL was used for this measurement. This paper describes the outline and the results of the joint measurement conducted in 2012 and 2014.
Eslinger, P. W.*; Bowyer, T. W.*; Achim, P.*; Chai, T.*; Deconninck, B*; Freeman, K.*; Generoso, S.*; Hayes, P.*; Heidmann, V.*; Hoffman, I.*; et al.
Journal of Environmental Radioactivity, 157, p.41 - 51, 2016/06
Times Cited Count：39 Percentile：70.29(Environmental Sciences)It is very important to understand the impact for CTBT stations caused by radioxenon emitted from nuclear facilities and medical isotope production facilities for detection of underground nuclear tests. Predictions of the impact on the CTBT radionuclide station in Germany of radioxenon emitted from the medical isotope production facility in Belgium were carried out by participants from seven nations using ATM (Atmospheric Transport Modeling) based on the emission data of radioxenon from this facility, as part of study on impact of radioxenon emitted from medical isotope production facilities on CTBT radionuclide stations.
Kijima, Yuichi; Yamamoto, Yoichi
Nihon Genshiryoku Gakkai-Shi ATOMO
, 58(3), p.156 - 160, 2016/03
JAEA has built and operated two radionuclide stations and a certified laboratory for monitoring of radionuclide out of facilities of the International Monitoring System (IMS) under the CTBT National Operation System of Japan. JAEA also has developed and operated the National Data Center for analysis and evaluation of radionuclide observation data obtained from the IMS station. In this paper, we explain the outline of the CTBT and the CTBT activities of JAEA, and introduce two examples of detection of some anthropogenic radionuclides including the monitoring case for the DPRK's 3rd nuclear test in February 2013 from all observational results obtained from the CTBT radionuclide stations in Japan.
Yamamoto, Yoichi; Kijima, Yuichi; Oda, Tetsuzo
no journal, ,
The Japanese NDC-2 estimated the movement of virtual radioactive plume by the Atmospheric Transport Modelling (ATM) simulations with regard to the DPRK 2016 event. The simulations were done in two hypothetical cases of coincident and delayed emission of radionuclides. The NDC-2 decided which IMS radionuclide stations should be monitored based on the simulation results. As the result, no radionuclides generated from the nuclear explosion were found in any IMS data obtained from the selected radionuclide stations in January. However, xenon-133 with high activity concentration above the normal background levels was detected 5 times at the Takasaki station in the middle of February. The NDC-2 estimated the location of emission source of the Xe-133 by ATM backward tracking simulations. Some ATM simulations and the analysis results by the NDC-2 are shown in the presentation.
Kijima, Yuichi; Yamamoto, Yoichi; Motohashi, Masashi*; Otsu, Takayuki*
no journal, ,
The CTBT National Operation System of Japan (NOSJ) consists of two NDCs, NDC-1 (Japan Weather Association; JWA) in charge of analysis of SHI data and NDC-2 (Japan Atomic Energy Agency; JAEA) in charge of analysis of RN data and ATM, and the Center for the Promotion of Disarmament and Non-Proliferation (CPDNP) which is the secretariat of NOSJ. The NDCs participated in the NDC preparedness exercise 2015 (NPE 2015). At first, NDC-2 made analysis of artificial (simulated) and real RN data for identification and quantification of RN, and ATM analysis for estimation of the possible source region. Then NDC-1 made analysis of seismic waveform to identify the epicenter using the result of NDC-2. Both NDCs tried to get a final conclusion collaboratively.
Yonezawa, Chushiro*; Yamamoto, Yoichi; Kijima, Yuichi; Kalinowski, M.*
no journal, ,
The authors present a summary report of the analysis results of ATM (Atmospheric Transport Model) and radionuclide (RN) data of the common exercise in the 2014 East Asia Regional NDC Workshop 2014 (EARNW 2014) held in Ulaanbaatar, Mongolia from 29 July to 1 August, 2014. The exercise scenario was that CTBT-relevant RNs released from a hypothetical target event were detected in particulate and noble gas samples at the Takasaki station (RN38), and the target event was inferred using estimated explosion time from La-140/Ba-140 ratio in the particulate samples. The possible source area was determined through ATM backward tracking of Xe-133. Real observation noble gas data by a certified IMS station and artificially prepared particulate data were used as the fictitious RN data in this exercise. The analysis results of the RN data by the participating NDCs were evaluated by comparing with the prepared values for the particulate and IDC/RRR for the noble gas data. The results of estimated explosion time were evaluated by comparing to the preset value. Released Xe-133 activity from the event and the observable radioactivity concentration of Xe-133 at the IMS station were compared among the reported ATM results.
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
no journal, ,
It is very important to understand the behavior of background of radioxenon at the view point of monitoring of underground nuclear tests. Although all nuclear power plants (NPPs) in Japan had been shut down from 15th September 2013 to 10th August 2015, Xe-133 had been sometimes detected far beyond normal background level of the activity concentration at the CTBT Takasaki station (JPX38) during the same period. Therefore, radiopharmaceutical production facilities (RPFs) in Japan can be considered as one of the potential emission sources of Xe-133 detected at JPX38 in this period. We make a study on the possibility of RPFs as the emission source of these Xe-133 detections at JPX38 by ATM simulation.
Kijima, Yuichi; Yamamoto, Yoichi
no journal, ,
JAEA as Japanese NDC-2 is in charge of monitoring radionuclide related to CTBT and performs analysis of radionuclide data and Atmospheric Transport Modelling (ATM) simulation to investigate the diffusion of radioactive plume. About two months later after the third nuclear test in DPRK on 12 February 2013 (DPRK-3), xenon-133 and xenon-131m were detected simultaneously far beyond normal background level of the activity concentration at the CTBT Takasaki station in Japan. From the aspect of isotope ratio and the result of ATM simulation, it is highly possible that these radioxenon isotopes are originated from DPRK-3. And there were detections of balium-140 and lanthanum-140 at the CTBT Okinawa station in Japan in 2010, and rutenium-106 in several CTBT stations in Eurasia in 2017. We report on these detections of artificial radionuclides in CTBT radionuclide stations.
Yamamoto, Yoichi; Kijima, Yuichi; Tomita, Yutaka
no journal, ,
This presentation summarizes JAEA's recent activities related to CTBT verification regime. To establish the global verification regime of CTBT for the nuclear tests, JAEA has been operating provisionally three facilities (two monitoring stations and one radionuclide laboratory) of the CTBT international monitoring system and a national data center for radionuclide monitoring. For the 6th nuclear test conducted by North Korea in September 2017, JAEA reported the analysis and evaluation results of data observed at the CTBT radionuclide monitoring stations to the national government etc. in a timely manner and thereby contributed to the evaluation by the national government based on the CTBT operation system in Japan. For the purpose of strengthening CTBTO's detection capability for nuclear tests, JAEA started new noble gas joint measurement project with CTBTO in Horonobe (Hokkaido) and Mutsu (Aomori) based on the Japanese government contribution in 2017.
Kijima, Yuichi; Yamamoto, Yoichi
no journal, ,
JAEA is in charge of monitoring radionuclide related to CTBT and performs analysis of radionuclide data and Atmospheric Transport Modelling (ATM) simulation to investigate the diffusion of radioactive plume. About two months later after the third nuclear test in DPRK on 12 February 2013 (DPRK-3), xenon-133 and xenon-131m were detected simultaneously far beyond normal background level of the activity concentration at the CTBT Takasaki station in Japan. From the aspect of isotope ratio and the result of ATM simulation, it is highly possible that these radioxenon isotopes are originated from the DPRK-3 event. And the CTBT Okinawa station in Japan detected balium-140 and lanthanum-140 in 2010, and many CTBT stations all over the world detected some artificial radionuclides after the Fukushima Daiichi Nuclear Power Plant accident in 2011. We report on these detection events of artificial radionuclides at CTBT radionuclide stations.
Yamamoto, Yoichi; Kijima, Yuichi; Tomita, Yutaka
no journal, ,
As a member of the CTBT National Operation System of Japan (NOSJ), JAEA monitors and evaluates radionuclides derived from nuclear tests. For this purpose, Takasaki and Okinawa radionuclide stations, Tokai radionuclide laboratory, and a national data center already were put in place and have been operated. This presentation introduces outline of NOSJ and each facility, the response to a nuclear test event, JAEA's recent activities etc.
Yamamoto, Yoichi; Kijima, Yuichi
no journal, ,
The radionuclide laboratory in Japan, JPL11, has analyzed 20 to 30 particulate filter samples per year which are obtained at the radionuclide monitoring stations in the CTBT International Monitoring System, IMS, network. The CINDERELLA filter is one of three kinds of filters to be analyzed by the radionuclide laboratories and is used in the ARAME systems which are in operation in some radionuclide monitoring stations of the IMS network as one of automatic particulate measurement systems. The presentation introduces the handling of the CINDERELLA filter samples done as the preparation before measurement at JPL11.
Tomita, Yutaka; Kumata, Masahiro; Wakabayashi, Shuji; Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
no journal, ,
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
no journal, ,
The International Noble Gas Experiment (INGE) is being carried out for global measurement networks of radioactive noble gas (xenon), as part of building of the international verification regime of the Comprehensive nuclear-Test-Ban Treaty (CTBT). Since there are many nuclear facilities and medical institutions in Japan and its neighboring countries, which may be possible sources of radioxenon, it is important to understand the behavior of normal radioxenon background for high-precision detection of underground nuclear tests. Therefore, for the purpose of the investigation on radioxenon background in Northeast Asia region, the measurement of radioxenon was conducted in Mutsu city, Aomori in 2012, and the results showed that radioxenon background in Mutsu was regionally specific and different from that in Takasaki. In 2014, the additional measurement was carried out at the same place for further investigation. This report describes the results of background measurement in Mutsu city in 2014.
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
no journal, ,
Following the claimed nuclear test in the Democratic People's Republic of Korea (DPRK) on 12 February 2013, spectral analysis of radionuclide and ATM simulation were performed by the NDC-2 in Japan which is in charge of analysing radionuclides. There was no detection of artificial radioactive particulates. However, there were several detections of radioxenon, although each activity concentration was not far beyond the normal background range. We tried to estimate upper limit of radioxenon release in the DPRK event by using IMS data and the ATM simulation. The upper limit of Xe-133 release was estimated about 10
- 10
Bq.
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
no journal, ,
It is very important to understand the impact of radioxenon emitted from nuclear facilities on the CTBT radionuclide stations for improvement of detection ability of underground nuclear tests. As part of study on the impact of radioxenon emitted from these facilities on the CTBT radionuclide stations, the 2nd ATM Challenge 2016 was carried out to quantify the impact of radioxenon from the Australian Nuclear Science and Technology Organisation (ANSTO) radiopharmaceutical plant in Australia by ATM analysis. JAEA/NDC participated in the 2nd ATM Challenge 2016 and performed ATM analysis by using the HYSPLIT code and the NCEP GDAS meteorological data. We report the analysis results.
Fujii, Takanari*; Otsu, Takayuki*; Yagi, Masanori*; Yonezawa, Chushiro*; Jih, R.*; Kalinowski, M.*; Kang, I.-B.*; Chi, H.-C.*; Yamamoto, Yoichi; Kijima, Yuichi
no journal, ,
As a part of East Asia Regional NDC Workshop 2014 Mongolia (EARNW2014), the common exercise took place for the purpose of investigation from both of radionuclide and waveform analysis. Each participating NDC analyzed distributed fictitious RN data and real SHI data including non-IMS to find and investigate candidate event. The Japanese NDC-1 (JWA) tried to locate and discriminate the event utilizing local seismic observation data such as NECESSArray (NorthEast China Extended SeiSmic Array) and Korean local data kindly provided by KIGAM. Signals from this event were detected at many stations in such non-IMS network, and it indicated that these local/regional seismic data could contribute largely to estimate more reliable event location and discrimination.
Kijima, Yuichi; Yamamoto, Yoichi; Oda, Tetsuzo
no journal, ,
More than 80% facilities (275 places) of the International Monitoring System prescribed in the Comprehensive Nuclear-Test-Ban Treaty (CTBT) have already been completed and have been substantially functioning as a global nuclear test monitoring. Of facilities installed in Japan, the JAEA has established 2 radionuclide stations which monitor radionuclides and 1 laboratory which performs detail analyses of samples sent from stations all over the world, and is operating them as certified facilities which meet technical requirements for the Treaty monitoring. The National Data Center installed in JAEA's site receives the data from station network and analyzes it routinely. This paper describes current status of the verification regime and JAEA's recent activities related to the CTBT such as DPRK's 3rd nuclear test event.
