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Tanaka S, Nishikawa M, Ichimasa Y, Nishi M. Activities of Tritium Studies in Japan. FUSION SCIENCE AND TECHNOLOGY 2017. [DOI: 10.13182/fst02-a22602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S. Tanaka
- The University of Tokyo Hongou, Bunkyo, Tokyo 113-8656, JAPAN
| | - M. Nishikawa
- Kyushu University Hakozaki, Higashi, Fukuoka 812-8581, JAPAN
| | - Y. Ichimasa
- Ibaraki University HBunkyo, Mito, Ibaraki 310-8512, JAPAN
| | - M. Nishi
- Japan Atomic Energy Research Institute Tokai, Ibaraki, 319-1195, JAPAN
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Du L, Shan J, Ma YH, Wang L, Qin LL, Pi L, Zeng YS, Xia ZH, Wang GH, Liu W. An improved combustion apparatus for the determination of organically bound tritium in environmental samples. Appl Radiat Isot 2016; 110:218-223. [PMID: 26868274 DOI: 10.1016/j.apradiso.2015.12.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 11/25/2015] [Accepted: 12/07/2015] [Indexed: 11/18/2022]
Abstract
This paper reports an improved combustion apparatus for the determination of organically bound tritium in environmental samples. The performance of this apparatus including the recovery rate and reproducibility was investigated by combusting lettuce and pork samples. To determine the factors for the different recovery rates of lettuce and pork and investigate whether the samples were completely oxidized, the ashes and exhaust gases produced by the combustion were analyzed. The results indicate that the apparatus showed an excellent performance in the combustion of environmental samples. Thus, the improvements conducted in this study were effective.
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Affiliation(s)
- Lin Du
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Shan
- Institute of Nuclear Science and Technology, University of South China, Hengyang 421001, China
| | - Yu-Hua Ma
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ling Wang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lai-Lai Qin
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Pi
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - You-Shi Zeng
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Zheng-Hai Xia
- CNNC Nuclear Power Operations Management Co., Ltd., Haiyan 314300, China
| | - Guang-Hua Wang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
| | - Wei Liu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
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Ota M, Nagai H, Koarashi J. Importance of root HTO uptake in controlling land-surface tritium dynamics after an-acute HT deposition: a numerical experiment. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2012; 109:94-102. [PMID: 22390945 DOI: 10.1016/j.jenvrad.2012.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 02/03/2012] [Accepted: 02/06/2012] [Indexed: 05/31/2023]
Abstract
To investigate the role of belowground root uptake of tritiated water (HTO) in controlling land-surface tritium (T) dynamics, a sophisticated numerical model predicting tritium behavior in an atmosphere-vegetation-soil system was developed, and numerical experiments were conducted using the model. The developed model covered physical tritiated hydrogen (HT) transport in a multilayered atmosphere and soil, as well as microbial oxidation of HT to HTO in the soil, and it was incorporated into a well-established HTO-transfer organically bound tritium (OBT)-formation model. The model performance was tested through the simulation of an existing HT-release experiment. Numerical experiments involving a hypothetical acute HT exposure to a grassland field with a range of rooting depths showed that the HTO release from the leaves to the atmosphere, driven by the root uptake of the deposited HTO, can exceed the HTO evaporation from the ground surface to the atmosphere when root water absorption preferentially occurs beneath the ground surface. Such enhanced soil-leaf-atmosphere HTO transport, caused by the enhanced root HTO uptake, increased HTO concentrations in both the surface atmosphere and in the cellular water of the leaf. Consequently, leaf OBT assimilation calculated for shallow rooting depths increased by nearly an order of magnitude compared to that for large rooting depths.
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Affiliation(s)
- Masakazu Ota
- Research Group for Environmental Science, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
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Koarashi J, Mikami S, Akiyama K, Asano T. Determination of chemical forms of 3H released to the atmosphere from the Tokai Reprocessing Plant. J Radioanal Nucl Chem 2005. [DOI: 10.1007/s10967-005-0477-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Determination of chemical forms of 3H released to the atmosphere from the Tokai Reprocessing Plant. J Radioanal Nucl Chem 2004. [DOI: 10.1007/s10967-004-0477-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Tanaka S, O'hira S, Ichimasa Y. Overview of tritium safety studies in Japan. FUSION ENGINEERING AND DESIGN 2002. [DOI: 10.1016/s0920-3796(02)00240-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Koarashi J, Amano H, Andoh M, Iida T, Moriizumi J. Estimation of 14CO2 flux at soil-atmosphere interface and distribution of 14C in forest ecosystem. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2002; 60:249-261. [PMID: 12054039 DOI: 10.1016/s0265-931x(01)00084-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To realize the dynamical behavior of 14C among exchangeable carbon reservoirs in terrestrial environment, a method for in situ determination of 14CO2 flux at soil-atmosphere interface and a high flow rate CO2 sampler were developed. This method allowed us to collect integrated quantity of CO2 for determining 14C activity over an extended time period under environmental conditions with minimal site disturbance. The 14CO2 flux from ground surface was estimated to be 1.59 x 10(-5) Bq m (-2) S (-1) in a forest floor with the method. The specific activities of 14C in environmental materials such as some biological and air samples were also determined in the vicinity of the place, where the flux measurement was made, to discuss the behavior of 14C in the forest ecosystem. The results indicated that fresh pine needles had a similar 14C specific activity to the atmospheric CO2 at the same height due to its fairly rapid equilibrium, 14C specific activity in the atmospheric CO2 has a concentration gradient near the ground surface and, at least in this site, CO2 with high 14C specific activity was generated by decomposition of soil organic matter which may be accumulated in soil as a result of former nuclear weapons tests.
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Affiliation(s)
- Jun Koarashi
- Department of Environmental Sciences, Japan Atomic Energy Research Institute, Naka-gun, Ibaraki-ken.
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