劉朋杰，張旖旎，劉天元

摘 要：核污染擴(kuò)散問(wèn)題是世界各國(guó)關(guān)注的問(wèn)題，尤其是在日本福島核事故發(fā)生之后，研究核素?cái)U(kuò)散問(wèn)題有利于輻射防護(hù)。本文建立了無(wú)風(fēng)與有風(fēng)條件下的核素?cái)U(kuò)散模型并將其應(yīng)用于軟件的開(kāi)發(fā)。據(jù) 定律和質(zhì)量守恒定律得出核素在無(wú)風(fēng)情況下隨時(shí)空的擴(kuò)散方程；借助概率論知識(shí)得出有風(fēng)情況下的高斯擴(kuò)散方程。考慮到地面反射的影響，排風(fēng)設(shè)備的沖力和熱排放的浮力等產(chǎn)生的煙羽抬升以及放射性物質(zhì)的衰變，對(duì)模型進(jìn)行了適當(dāng)?shù)母倪M(jìn)。基于得出的結(jié)果用Python 編程繪圖，得出的結(jié)論與實(shí)際分析一致，驗(yàn)證了模型的可靠性。

關(guān)鍵詞：核素?cái)U(kuò)散模型 高斯煙羽模型Fick 定律Python

Preliminary Development and Validation of a Radionuclide Atmospheric Diffusion Process Based on Python

LIU Pengjie1，ZHANG Yini1，LIU Tianyuan1

（1.School of Nuclear Science and Engineering， North China Electric Power University， Beijing 102206， China）

Abstract： The issue of proliferation of nuclear pollution is a matter of concern to all countries in the world， especially after the nuclear accident in Fukushima， Japan. Studying the proliferation of nuclide is conducive to nuclear safety. This paper establishes a nuclide diffusion model under windless and windy conditions， and applies it to the development of software. First， according to the law of Fick and conservation of mass， the diffusion equation of nuclide at any time and in the absence of wind is obtained. Secondly， the Gaussian diffusion equation in windy conditions is derived from the knowledge of probability theory. Considering the influence of ground reflections， plume rise resulted from exhaust equipment impulse and thermal discharge buoyancy and decay of radioactive material， this article makes some appropriate modifications to the model. Finally， based on the results obtained， Python is used to program and draw， the conclusion got from the figure is consistent with the actual analysis， verifying the robustness of the model.

Keywords： Nuclide diffusion model， Gaussian plume model， the law of Fick， Python