Kim Cheol-Hee, Song Chang-Keun, Lee Sang-Hyun, Song Sang-Keun
Division of Earth Environmental System, Pusan National University, 30 Jangjeon-Dong, Geumjeong-Gu, Busan 609-735, Republic of Korea.
J Environ Radioact. 2008 Oct;99(10):1644-52. doi: 10.1016/j.jenvrad.2008.05.002. Epub 2008 Jun 30.
In order to simulate the impact of mesoscale wind fields and to assess potential capability of atmospheric Lagrangian particle dispersion model (LPDM) as an emergency response model for the decision supports, two different simulations of LPDM with the mesoscale prognostic model MM5 (Mesoscale Model ver. 5) were driven. The first simulation of radioactive noble gas (85Kr exponent) emitted during JCO accident occurred from 30 September to 3 October 1999 at Tokai, Japan showed that the first arriving short pulse was found in Tsukuba located at 60 km away from the accidental area. However, the released radioactive noble gas was transported back to the origin site about 2 days later due to the mesoscale meteorological wind circulation, enhancing the levels of 85Kr with the secondary peak in Tsukuba. The second simulation of atmospheric dilution factors (the ratio of concentration to the emission rate, chi/Q), during the underground nuclear test (UNT) performed by North Korea showed that high chi/Q moved to the eastward and extended toward southward in accordance with the mesoscale atmospheric circulations generated by mesoscale prognostic model MM5. In comparison with the measurements, the simulated horizontal distribution patterns of 85Kr during the JCO are well accord with that of observation in Tsukuba such as the existence of secondary peak which is associated with the mesoscale circulations. However, the simulated level of 85Kr anomaly was found to be significantly lower than the observations, and some interpretations on these discrepancies were described. Applications of LPDM to two mesoscale emergency response dispersion cases suggest the potential capability of LPDM to be used as a decision support model provided accurate emission rate of accident in case of a large accident.
为了模拟中尺度风场的影响，并评估大气拉格朗日粒子扩散模型（LPDM）作为决策支持应急响应模型的潜在能力，利用中尺度预报模型MM5（中尺度模型第5版）对LPDM进行了两种不同的模拟。对1999年9月30日至10月3日在日本东海发生的日本核燃料转换公司（JCO）事故期间排放的放射性惰性气体（85氪指数）进行的首次模拟显示，在距离事故区域60公里的筑波发现了首个到达的短脉冲。然而，由于中尺度气象风环流，释放的放射性惰性气体在大约两天后被输送回原点，从而提高了筑波85氪的水平并出现了次峰。对朝鲜进行的地下核试验期间大气稀释因子（浓度与排放率之比，χ/Q）的第二次模拟表明，高χ/Q值随着中尺度预报模型MM5产生的中尺度大气环流向东移动并向南扩展。与测量结果相比，JCO事故期间85氪的模拟水平分布模式与筑波的观测结果非常吻合，例如与中尺度环流相关的次峰的存在。然而，发现85氪异常的模拟水平明显低于观测值，并对这些差异进行了一些解释。将LPDM应用于两个中尺度应急响应扩散案例表明，在发生重大事故时，只要事故排放率准确，LPDM有潜力用作决策支持模型。
