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Soil-to-Crop Transfer Factors of Naturally Occurring Radionuclides and Stable Elements for Long-Term Dose Assessment
https://repo.qst.go.jp/records/68867
https://repo.qst.go.jp/records/68867e0c10ca9-657e-48ac-926f-78e084e85b02
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2007-03-07 | |||||
| タイトル | ||||||
| タイトル | Soil-to-Crop Transfer Factors of Naturally Occurring Radionuclides and Stable Elements for Long-Term Dose Assessment | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Uchida, Shigeo
× Uchida, Shigeo× Tagami, Keiko× 内田 滋夫× 田上 恵子 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Soil-to-crop transfer factor (TF) is a key parameter that directly affects the internal dose assessment for the ingestion pathway, however, obtaining TFs of various long-lived radionuclides occurred during operation of nuclear power plants is difficult because most of them could not be found in natural environments; we still can observe fallout 90Sr and 137Cs, but their concentrations are extremely low in crop samples. Radiotracer experiments would give us some knowledge, however, short period studies and/or laboratory studies are not sufficient used in mathematical models for precise long-term radiological assessment. Other possible method to provide TFs is to measure naturally occurring radionuclides and stable elements in soil and crop samples as analogues of long-lived radionuclides. In this study, we collected crops and their associated soils throughout Japan and measured more than 50 elements to obtain TFs under equilibrium conditions. 62 upland field crops, such as cabbage, potato, Japanese radish, and associated soils were collected throughout Japan at their harvest season. The soil samples were air-dried and passed through a 2-mm mesh sieve. Each dried and crashed sample, 100 mg for soil and 500 mg for crops, were digested with mineral acids using a microwave digester. Then the digested was dissolved in 20 mL of 2% nitric acid. Elements including Se, Cs, Th and U in both crop and soil samples were measured by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. The TFs were calculated for 42 elements (Li, Na, Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Y, Mo, Cd, Sn, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tl, Pb, Th and U) from their concentrations in both crop and soil samples. The TF is defined as the concentration of an isotope in a crop (in Bq/kg or mg/kg dry weight) divided by the concentration of the isotope in soil (in Bq.kg or mg/kg dry weight). Probability distributions of TFs were usually log-normal type so that geometric mean (GM) were calculated. The GM of TF for each element was from 2.3E-4 (Al) to 2.1 (K). The values for the elements of interest from the viewpoint of long-term dose assessment were from 5.4E-3 to 3.2E-1 for Se, from 7.9E-5 to 7.7E-2 for Cs, from 9.4E-6 to 2.7E-2 for Th and from 2.6E-5 to 2.8E-2 for U. Leafy vegetable showed the highest TFs for all the elements among the crop groups. It was clear that these data were usually within the 95% confidence limits of TFs compiled by IAEA in Technical Report Series 364. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | the 33th Waste Management Symposium (WM'07) | |||||
| 発表年月日 | ||||||
| 日付 | 2007-03-01 | |||||
| 日付タイプ | Issued | |||||
