Pathway: A Simulation Model of Radionuclide Transport through Agricultural Food Chains

Kirchner, Thomas B.; Whicker, F.W.; Otis, Mark D.

doi:10.1016/b978-0-444-42179-1.50107-3

Cited by 7 publications

(4 citation statements)

References 10 publications

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“…Among numerous models, empirical models based on the soil-to-plant transfer factor are the simplest, assuming that the activity concentration of RCs in crop or crop parts is linearly proportional to that in soil. This approach is adopted not only in the so-called equilibrium model (Yasuda 1995) but is also used in dynamic models, such as PATHWAY (Kirchner et al 1983). Although a database on the transfer factor was compiled (IAEA 2009), the results showed large variability even for the same crop in the same soil groups.…”

Section: Development In the Functions Of Radio-cesium Transfer Modelsmentioning

confidence: 99%

Models for Assessment on the Uptake of Radio-cesium by Rice Using Soil Parameters Calibrated for Paddy Fields in Fukushima Prefecture

Yagasaki

2022

JARQ

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Two recently developed models of radio-cesium (RCs) transfer from soil to rice grains that were parameterized and ready-to-use for paddy fields in Fukushima were reviewed to establish modelbased countermeasures for food safety management in Fukushima. A probability density function model of the transfer factor from soil to rice grains based on soil exchangeable potassium (K) was compared with that of a rice grain RCs concentration model on the basis of the concentration of soil exchangeable RCs and soil exchangeable K. The relevance between these two models was demonstrated using soil exchangeable RCs as a quantitative index of the availability of soil RCs and observed data. The results indicate that the probability density of the transfer factor is affected by soil exchangeable RCs and that the use of a log-normal distribution in the model is justified by the observed distribution pattern of soil exchangeable RCs. This finding improves the accountability of the differences in the modeled probability densities for different regions and helps design countermeasures using the two models for different purposes, such as precautions for K fertilization or conservative risk assessment of shipping restrictions.

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Section: Development In the Functions Of Radio-cesium Transfer Modelsmentioning

confidence: 99%

Models for Assessment on the Uptake of Radio-cesium by Rice Using Soil Parameters Calibrated for Paddy Fields in Fukushima Prefecture

Yagasaki

2022

JARQ

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“…Ingestion of contaminated food is a significant source of dose in many cases (Anspaugh et al 1988). States (Kirchner et al 1983). Contaminated milk is a major source of internal dose resulting from tests of nuclear weapons ) and nuclear accidents (Eisenbud 1987, Konstantinov and.…”

Section: Introductionmentioning

confidence: 96%

“…We studied the influence of different environmental, physiological, and management factors on radionuclide concentrations in milk predicted by PATHWAY, a model developed for radionuclide transport through semi-arid agroecosystems of the southwestern United States (Kirchner et al 1983). Contaminated milk is a major source of internal dose resulting from tests of nuclear weapons ) and nuclear accidents (Eisen bud 1987, Konstantinov and.…”

Section: Introductionmentioning

confidence: 99%

Contaminant Transport through Agroecosystems: Assessing Relative Importance of Environmental, Physiological, and Management Factors

Breshears¹,

Kirchner²,

Whicker³

1992

Ecological Applications

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Agroecosystems can become contaminated by atmospherically released radionuclides. The subsequent concentrations of radionuclides in foods are dependent on numerous environmental, physiological, and management factors. We compared four approaches for estimating the relative importance of several of these factors in determining concentrations of I and Cs in milk. A series of sensitivity analyses with Monte Carlo and full-factorial sampling designs was conducted on the PATHWAY model, which simulates radionuclide transport through an agroecosystem. Sensitivity of time-integrated concentrations in milk was estimated as a function of the time of year that fallout was deposited and as a function of time following a spring deposition. The dominant parameters affecting time-integrated concentrations of I in milk were the initial fraction of radionuclides deposited on vegetation, timing and amount of pasture consumption, and the production rate of milk. For time-integrated concentrations of the longer-lived Cs in milk, resuspension was a dominant parameter and pasture use was less important. The sampling designs were compared by ranking the parameters to which the model output is sensitive. The three sampling designs based on parameter variances produced sets of ranks that were similar to each other but differed from the ranking produced by the sampling design based on parameter magnitude. The results indicate which data are most crucial for real-time calculations following an accident and how subsequent dose from ingestion can be most effectively reduced, provide insight into model behavior, and help prioritize future research. This paper demonstrates the importance of variance-based sensitivity analysis.

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“…"원자력 이용시설 주변 방사선환경조사 및 평가" 에서 검출된 토양 중 90 Sr의 방사능 농도범위(<0.172-1.92) 이 내의 값이었다 [1]. 137 Cs과 90 Sr의 평균비(Table 2)는 9.67로, 이는 일반적 인 초기 방사성낙진에 의한 농도비(약1.7)보다 훨씬 큰 값이다 [7]. 그 이유로는 토양에 존재하고 있는 안정 strontium과 두 핵종의 토양교질입자에 대한 흡착 용이 성 차이에 의해 시간경과에 따라 2가 이온인 strontium 은 토양의 깊은 층으로 많은 이동을 하는 반면, 1가 이 온인 cesium은 대부분이 여전히 표층토양에 존재하기 때문에 비는 점점 더 큰 값을 가지게 되는 것이다 [4,8,9].…”

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Distributions of <sup>137</sup>Cs and <sup>90</sup>Sr in the Soil of Uljin, South Korea

Song¹,

Kim²,

Maeng³

et al. 2016

J Radiat Prot Res

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Background: For the purpose of baseline data collection and enhancement of environmental monitoring the distribution studies of 137 Cs and 90 Sr in the soil of Uljin province was performed and the relation between surface soil activities and soil properties (pH, TOC and median of the surface soil) was analyzed. Materials and Methods: For 14 spots within 10 km from the NPP surface soil samples were collected and soils for depth profile were sampled for 3 spots in April 2011. Using γ-ray spectrometry with HPGe detector, the concentrations of 137 Cs were determined and the concentrations of 90 Sr were measured by counting β-activity of 90 Y (in equilibrium with 90 Sr) in a gas flow proportional counter. Results and Discussion: The concentration ranges of 137 Cs and 90 Sr were <0.479-39.6 Bq‧ (kg-dry) -1 (avg. 7.51 Bq‧(kg-dry) -1 ) and 0.209-1.85 Bq‧(kg-dry) -1 (avg. 0.74 Bq‧(kg-dry) -1 ) which were similar to the reported values from other regions in Korea. The activity ratio of 137 Cs to 90 Sr in surface soils was around 9.67, which is much bigger than the initial value of 1.75 for worldwide fallouts because of faster downward movement of 90 Sr after fallout than that of 137 Cs. For depth profile studies soils were collected down to 40 cm depth for the locations of Deokgu, Hujeong and Maehwa. The 137 Cs concentration distribution of the first two showed maximum values at top soils and decreased rapidly in exponential manner, while 90 Sr showed two local maximum values for soils near top and about 30 cm depth. Through linear fittings between the 137 Cs and 90 Sr concentrations of surface soil and pH, TOC and median of the surface soil, the only probable relationship obtained was between 137 Cs and TOC (determination coefficient R 2 =0.6). Conclusion: The concentration ranges of 137 Cs and 90 Sr in Uljin were similar to the reported values from other regions in Korea. The only probable relationship obtained between activities and soil properties was between 137 Cs and TOC.

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Pathway: A Simulation Model of Radionuclide Transport through Agricultural Food Chains

Cited by 7 publications

References 10 publications

Models for Assessment on the Uptake of Radio-cesium by Rice Using Soil Parameters Calibrated for Paddy Fields in Fukushima Prefecture

Models for Assessment on the Uptake of Radio-cesium by Rice Using Soil Parameters Calibrated for Paddy Fields in Fukushima Prefecture

Contaminant Transport through Agroecosystems: Assessing Relative Importance of Environmental, Physiological, and Management Factors

Distributions of <sup>137</sup>Cs and <sup>90</sup>Sr in the Soil of Uljin, South Korea

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