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Gao C, Liu SY, Feng JD, Hu SM, Jiang W, Lu ZT, Ritterbusch F, Wang WH, Yang GM, Zhao LU. Monitoring atmospheric 85Kr by atom counting. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 233:106604. [PMID: 33813356 DOI: 10.1016/j.jenvrad.2021.106604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/19/2021] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Radioactive 85Kr is a major gaseous fission product emitted into the air by the nuclear fuel reprocessing industry. Measuring atmospheric 85Kr has applications in environmental monitoring, atmospheric transport model validation and dating of environmental water samples, including groundwater, sea water and glacier ice. We present an ultra-sensitive method for fast analysis of atmospheric 85Kr at 10-5 parts per trillion level. This method is based on laser cooling and trapping and is capable of counting individual 85Kr atoms. Measurements at the 3% precision level can be made on krypton extracted from 1L STP of air with a turnaround time of 1.5 h. Moreover, we have realized a system for continuous air sampling over days to weeks. Based on this atom-counting technology and a portable air sample integrator we have realized atmospheric 85Kr baseline monitoring in Hefei, China, for over 20 months. The technological advances presented in this work lay the ground for a global atmospheric 85Kr monitoring network.
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Affiliation(s)
- Chao Gao
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Si-Yu Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Jie D Feng
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Shui-Ming Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Wei Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China.
| | - Zheng-Tian Lu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Florian Ritterbusch
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Wen-Hao Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
| | - Guo-Min Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China.
| | - Lei U Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, China
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Li Q, Liu S, Wang S, Fan Y, Zhao Y, Chen Z, Zhang X, Jia H, Chang Y, An S, Shi J, Zhu Y. Radioactivity measurement of 85Kr by using anti-cosmic HPGe γ spectrometer. Appl Radiat Isot 2021; 176:109846. [PMID: 34214912 DOI: 10.1016/j.apradiso.2021.109846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 11/15/2022]
Abstract
In order to improve the detection sensitivity of 85Kr, an anti-cosmic HPGe γ spectrometer was established and a specific Marinelli beaker was designed for 85Kr measurement. Comparing to the non-anticoincidence γ spectrum, the integral background counts rate range from 20 to 2400 keV was reduced by a factor of 5.17 using anticoincidence shielding. The minimum detectable activity of 85Kr was 10.5 Bq within 24 h measurement in standard mode and that of 3.99 Bq in anticoincidence mode. The activity concentration of atmospheric 85Kr was preliminarily measured to be an average of 1.30 Bq/m3 in Beijing and corresponding minimum detectable concentration was 0.2 Bq/m3.
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Affiliation(s)
- Qi Li
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China.
| | - Shujing Liu
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Shilian Wang
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China.
| | - Yuanqing Fan
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Yungang Zhao
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China; Key Laboratory of Beam Technology of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing, China
| | - Zhanying Chen
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Xinjun Zhang
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Huaimao Jia
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Yinzhong Chang
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Shaohang An
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Jianfang Shi
- CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory, Beijing, China
| | - Yuchen Zhu
- School of Nuclear Science and Technology, University of South China, Hengyang, China
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Chen CF, Yang LT, Huang YJ, Shang-Guan ZH, Guo GY, Yao JL, Sha XD. A study on 85Kr measurement with an internal gas proportional counter. Appl Radiat Isot 2019; 155:108948. [PMID: 31655352 DOI: 10.1016/j.apradiso.2019.108948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 10/15/2019] [Accepted: 10/15/2019] [Indexed: 10/25/2022]
Abstract
A measurement method of 85Kr using an internal gas proportional counter (IGPC) is presented in this study. The operation conditions of the IGPC were determined and optimized, including the operating voltage, pressure, sample volume, interference from other gas components such as nitrogen or air, and mitigation of the memory effect. The IGPC was calibrated using certified standards, and the detection efficiency was approximately 58% for typical samples. A lower limit of detection of approximately 0.11 MBq/m3(Kr) was achieved after counting for 5 h with 1 mL pure Kr, corresponding to the atmospheric activity concentration of 0.18 Bq/m3 (air). It was shown that the IGPC could be used effectively for measuring 85Kr.
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Affiliation(s)
- Chao-Feng Chen
- Suzhou Nuclear Power Research Institute Co., Ltd, Suzhou, 215004, China
| | - Li-Tao Yang
- Suzhou Nuclear Power Research Institute Co., Ltd, Suzhou, 215004, China
| | - Yan-Jun Huang
- Suzhou Nuclear Power Research Institute Co., Ltd, Suzhou, 215004, China.
| | | | - Gui-Ying Guo
- Suzhou Nuclear Power Research Institute Co., Ltd, Suzhou, 215004, China
| | - Jian-Lin Yao
- Suzhou Nuclear Power Research Institute Co., Ltd, Suzhou, 215004, China
| | - Xiang-Dong Sha
- Suzhou Nuclear Power Research Institute Co., Ltd, Suzhou, 215004, China
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Experimental facility for the production of reference atmosphere of radioactive gases (Rn, Xe, Kr, and H isotopes). Appl Radiat Isot 2019; 155:108934. [PMID: 31629295 DOI: 10.1016/j.apradiso.2019.108934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 10/07/2019] [Accepted: 10/09/2019] [Indexed: 11/23/2022]
Abstract
Radioactive gases are of great interest for environmental measurements and can be distinguished in two categories. The natural radionuclides such as the isotopes of radon (222Rn and 220Rn), and the anthropogenic radionuclides coming from fission products (isotopes of Xe and 85Kr) and activation products (3H and 37Ar). Gas monitoring in the environment is an important issue for radioprotection and for the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which both require metrological traceability of these gases. For this purpose, two gas chambers, of 42 L and 125 L, have been conceived and built at the LNE-LNHB to produce reference atmospheres of various gas mixtures. These chambers were created in order to provide any radioactive gas atmosphere with a wide range of activity concentrations (Bq·m-3 to MBq·m-3). The goal of this setup is to be representative of the different environmental conditions for detector qualification and to perform studies of radioactive gas absorption in materials of interest. As a result, the 2 chambers used in this experimental facility are designed to work from vacuum pressure to atmospheric pressure, with a constant activity concentration for any radioactive gas, and under dry to high humidity conditions. It can also be used in a static mode, in which the activity concentration will follow the radioactive decay of the gas. In this paper, the characterization of the chambers will be discussed. These two chambers are combined with different primary standards established by the LNE-LNHB. As the production of the reference atmosphere depends on the primary standard method, we present the details for each atmosphere production, which require a well-known volume, pressure or a direct activity concentration measurement.
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Nitta W, Sanada T, Isogai K, Schlosser C. Atmospheric85Kr and133Xe activity concentrations at locations across Japan following the Fukushima Dai-ichi Nuclear Power Plant accident. J NUCL SCI TECHNOL 2014. [DOI: 10.1080/00223131.2014.888960] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Momoshima N, Inoue F, Sugihara S, Shimada J, Taniguchi M. An improved method for 85Kr analysis by liquid scintillation counting and its application to atmospheric 85Kr determination. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2010; 101:615-621. [PMID: 20430490 DOI: 10.1016/j.jenvrad.2010.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 03/04/2010] [Accepted: 03/23/2010] [Indexed: 05/29/2023]
Abstract
Atmospheric (85)Kr concentration at Fukuoka, Japan was determined by an improved (85)Kr analytical method using liquid scintillation counting (LSC). An average value of 1.54 +/- 0.05 Bq m(-3) was observed in 2008, which is about two times that measured in 1981 at Fukuoka, indicating a 29 mBq y(-1) rate of increase as an average for these 27 years. The analytical method developed involves collecting Kr from air using activated charcoal at liquid N(2) temperature and purifying it using He at dry ice temperature, followed by Kr separation by gas chromatography. An overall Kr recovery of 76.4 +/- 8.1% was achieved when Kr was analyzed in 500-1000 l of air. The Kr isolated by gas chromatography was collected on silica gel in a quartz glass vial cooled to liquid N(2) temperature and the activity of (85)Kr was measured with a low-background LS counter. The detection limit of (85)Kr activity by the present analytical method is 0.0015 Bq at a 95% confidence level, including all propagation errors, which is equivalent with (85)Kr in 1.3 l of the present air under the analytical conditions of 72.1% counting efficiency, 0.1597 cps background count rate, and 76.4% Kr recovery.
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Affiliation(s)
- Noriyuki Momoshima
- Radioisotope Center, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan.
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Kemp RS, Schlosser C. A performance estimate for the detection of undeclared nuclear-fuel reprocessing by atmospheric 85Kr. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2008; 99:1341-1348. [PMID: 18504064 DOI: 10.1016/j.jenvrad.2008.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 04/11/2008] [Accepted: 04/12/2008] [Indexed: 05/26/2023]
Abstract
To test the sensitivity of using atmospheric (85)Kr to detect undeclared separation of plutonium from irradiated nuclear-reactor fuel, measurements of atmospheric (85)Kr taken in Tsukuba, Japan are analyzed to determine: (1) a lower limit of detection for discovering anthropogenic (85)Kr emissions, (2) the probability of detecting plutonium separation at the Tokai Reprocessing Plant, and (3) the extent to which these results can be generalized to other sites. A LLD of at least 3.4 sigma=0.14 Bq/m(3) with a theoretical false-positive rate of 0.05% is recommended for safeguards' purposes. At this threshold, the continuous separation of 100, 300, and 900 g equivalent weapon-grade plutonium per day was found to correspond to 10%, 50%, and 80% probability of detection, respectively. The smallest detected concentration was for the continuous separation of 45 g/day, with a probability of detection of about 0.6%. It was found that the detection rate is determined predominantly by the weather.
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Affiliation(s)
- R Scott Kemp
- Program on Science and Global Security, Princeton University, 221 Nassau Street, Princeton, NJ 08544, USA.
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Yamaguchi N, Nakano M, Tanida H, Fujiwara H, Kihou N. Redox reaction of iodine in paddy soil investigated by field observation and the I K-Edge XANES fingerprinting method. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2006; 86:212-26. [PMID: 16242819 DOI: 10.1016/j.jenvrad.2005.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 08/28/2005] [Accepted: 09/05/2005] [Indexed: 05/05/2023]
Abstract
In order to elucidate the cause for the leaching of iodine in a flooded paddy field, we investigated the transformation of an iodine species affected by the water management of the paddy field. The increased concentration of iodide (I(-)) in soil solution of a flooded paddy field suggested that I(-) was leached from the soil under anaerobic conditions. The post-edge feature of X-ray absorption near-edge structure (XANES) for iodate (IO(3)(-)) spiked to soil totally disappeared after anaerobic incubation of the soils, and I(-) was dissolved in the solution. On the other hand, I(-) in contact with the soil was not likely to be oxidized to IO(3)(-) under aerobic incubation. Iodine was leached out in soil solution as I(-) under anaerobic conditions, whereas part of the iodine species was retained by soil as I(2) or organoiodine both under anaerobic and aerobic conditions.
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Affiliation(s)
- N Yamaguchi
- National Institute for Agro-Environmental Sciences, 3-1-3 Kan-nondai, Tsukuba, Ibaraki 305-8604, Japan.
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Winger K, Feichter J, Kalinowski MB, Sartorius H, Schlosser C. A new compilation of the atmospheric 85krypton inventories from 1945 to 2000 and its evaluation in a global transport model. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2005; 80:183-215. [PMID: 15701383 DOI: 10.1016/j.jenvrad.2004.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Revised: 09/02/2004] [Accepted: 09/29/2004] [Indexed: 05/24/2023]
Abstract
This paper gives the yearly (85)Kr emissions of all known reprocessing facilities, which are the main sources of (85)Kr in the atmosphere since 1945, for the years 1945 until 2000. According to this inventory 10,600 PBq (Peta=10(15)) of (85)Kr have been globally emitted from the year 1945 until the end of 2000. The global atmospheric inventory at the end of the year 2000 amounts to 4800 PBq. These emissions have been incorporated into the ECHAM4 atmospheric general circulation model as point sources. Monthly mean model results are compared with measurements made at different locations and times. The influence of each source on the measured concentrations at various locations is studied. The calculated concentrations are found to give reasonably good agreement with the observations, indicating that the emission inventory is realistic. Although, at all northern hemispheric observation sites the model tends to slightly overestimate the concentrations. A possible reason for this overestimation can be found in model features (coarse resolution in time and space). The most prominent discrepancy that is consistently repeated at all northern hemispheric stations occurs in the early 1990s. This could most likely be related to an overestimate of sources. Possibly, the Russian emissions declined earlier than assumed in the current database. Another discrepancy between observations and simulations indicating an incompleteness of the release data is found at some southern hemispheric sites. The variability of their observations could only be explained by regional sources. However, several spikes occur after 1992 when no reprocessing facility is known to be in operation in the southern hemisphere. Production of isotopes for radiopharmaceuticals like technetium-99m from highly enriched uranium is the most likely explanation.
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Affiliation(s)
- K Winger
- Max-Planck-Institut für Meteorologie, Bundesstrasse 55, D-20146 Hamburg, Germany.
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Hirota M, Nemoto K, Wada A, Igarashi Y, Aoyama M, Matsueda H, Hirose K, Sartorius H, Schlosser C, Schmid S, Weiss W, Fujii K. Spatial and temporal variations of atmospheric 85Kr observed during 1995-2001 in Japan: estimation of atmospheric 85Kr inventory in the Northern Hemisphere. JOURNAL OF RADIATION RESEARCH 2004; 45:405-413. [PMID: 15613786 DOI: 10.1269/jrr.45.405] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Atmospheric 85Kr concentrations have been continuously monitored since 1995 at the Meteorological Research Institute (MRI) in Tsukuba, Japan. They have also been observed once a year at several stations over the Japanese islands since 1995. The annual growth rate of the background atmospheric 85Kr concentrations in Tsukuba was 0.03 Bq x m(-3) x yr(-1) during 1996-2001. The atmospheric 85Kr concentrations at several stations over Japan were within the range of the annual variations in Tsukuba. However, higher and lower 85Kr concentrations in early winter, compared with those in Tsukuba (36.1 degrees N, 140.1 degrees E), occurred in Sapporo (43.1 degrees N, 141.3 degrees E) and Ishigaki (24.3 degrees N, 124.2 degrees E), respectively. The reason for this is that Sapporo is covered by a continental air mass, some from European sources, whereas Ishigaki is still covered by a subtropical air mass. The Northern Hemispheric background 85Kr concentrations from 1994 to 2001 was calculated from the 85Kr inventory and the release rate of 85Kr from the nuclear fuel reprocessing plants in Europe. Calculated 85Kr concentrations in surface air were in good agreement with annual average observed values at the MRI, Tsukuba. The global atmospheric inventory of 85Kr in December 2001 was also estimated to be approximately 5 EBq by using observed data in Tsukuba.
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