某核電廠近岸海域放射性核素遷移特征探討
發(fā)布時間:2018-01-16 00:15
本文關(guān)鍵詞:某核電廠近岸海域放射性核素遷移特征探討 出處:《海洋科學進展》2016年02期 論文類型:期刊論文
【摘要】:濱海核電廠運行時會有少量的放射性核素通過液態(tài)途徑進入海洋環(huán)境中,在掌握其海域水動力環(huán)境的基礎(chǔ)上,開展放射性核素遷移研究具有重要意義;谀澈穗娬窘逗S虻乃碌匦魏退臈l件,通過潮位、流速、流向的率定,構(gòu)建水動力環(huán)境模型,模擬研究區(qū)的潮流運動過程和特征,為放射性核素遷移擴散提供基本流場背景。以核素131I為例,采用恒定速率1Bq/L活度濃度持續(xù)排放,用實測兩個半月潮模擬核素遷移過程,分析放射性核素131I在該海域的時間和空間分布規(guī)律。結(jié)果表明:1)隨著時間推移,核素逐漸向外海域擴散,但擴散速度較慢;隨著距離增大,海域中核素活度濃度呈幾何倍數(shù)快速下降;廠址東北方向岸邊核素活度濃度較高,在一個月后逐步達到穩(wěn)定,約比排放活度濃度低兩個數(shù)量級。2)漲潮時核素活度濃度范圍較小,落潮時核素活度濃度范圍快速擴大,相同核素活度濃度面積為漲潮時的2~3倍。3)排放初期,各處核素活度濃度均隨時間迅速增加,隨后趨于穩(wěn)定;不同位置的活度濃度隨著潮汐交替漲落,不斷波動,漲潮時活度濃度較低,落潮時活度濃度較高;不同位置的平均活度濃度隨著潮汐交替漲落,不斷波動,大潮期間活度濃度較高,小潮期間活度濃度快速降低。
[Abstract]:A small amount of radionuclides will enter the marine environment through liquid way when the coastal nuclear power plant is in operation, on the basis of mastering the hydrodynamic environment of the coastal nuclear power plant. The study of radionuclide migration is of great significance. Based on the underwater topography and hydrological conditions in the coastal waters of a nuclear power plant, the hydrodynamic environment model is constructed by determining the tidal level, velocity and direction. The flow process and characteristics of the studied area are simulated to provide the basic flow field background for radionuclide migration and diffusion. Taking 131I as an example, the constant rate of 1Bq / L activity concentration is used to continuously discharge the radionuclides. The time and spatial distribution of radionuclide 131I in the sea area is analyzed by simulating the radionuclide migration process with two and a half months observed. The results show that the radionuclide gradually diffuses to the outer sea area with the passage of time. But the diffusion rate is slow. With the increase of distance, the concentration of radionuclide activity decreased rapidly. The concentration of radionuclide activity in the northeast direction of the site is relatively high and gradually stabilized after one month, which is about two orders of magnitude lower than the discharge activity concentration. 2) the range of radionuclide activity concentration in the high tide is relatively small. The range of radionuclide activity concentration at the ebb tide expands rapidly, and the area of the same activity concentration is 3 times of that of the rising tide. At the beginning of discharge, the activity concentration of various nuclides increases rapidly with time, and then tends to be stable. The activity concentration at different positions fluctuates continuously with the tide fluctuating alternately. The activity concentration is lower at the high tide and higher at the ebb tide. The mean activity concentration at different positions fluctuates continuously with the change of tide. During the spring tide, the activity concentration is higher, and the activity concentration decreases rapidly during the low tide.
【作者單位】: 環(huán)境保護部核與輻射安全中心;
【基金】:科技基礎(chǔ)性工作專項——我國環(huán)境放射性水平精細圖譜建設(shè)(2015FY10800)
【分類號】:X771;X55
【正文快照】: 核電廠在正常運行期間,液態(tài)放射性流出物與冷卻水充分混合后,隨冷卻水(排水)一起排入受納水體,從而向水環(huán)境排放少量的放射性核素。潛在的放射性物質(zhì)泄漏污染也是核電廠事故時面臨的主要環(huán)境問題。2011-03-11,日本福島第一核電站發(fā)生了嚴重事故,大量放射性物質(zhì)通過液態(tài)途徑進,
本文編號:1430697
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