In numerical simulation of the air flow around Daya Bay nuclear power station (NPS),a simplified data assimilation method is used to restrain forecasting errors that are caused by the uneven distribution of observation data in time and space.The effect of data assimilation on the initialization field model is analyzed.It shows that the method restrains errors in initialization field and in model significantly.

Based on the model of the electron beam irradiating the matter having only single kind of atom and the elctron multiply scattering theory,this paper has constructed a scattering unit model mirroring the structure of the amprphous materials which have the characteristic of short range order but long range disorder.The electron energy loss distributions are calculated by means of Monte Carlo simulation and transport equation in the scattering unit model.In addition,the structure property of materials including several kinds of atoms are took into account.The calculatd results are given and discussed.

In this paper, we calculated the radioactive Concentration distribution of radioactive waste water, the temperature distribution of cooling water which drained and the effect of impingement from the Dayawan Nuclear Power Station on nearby waters range, discussed and analysed some problems of Computational results and computatin with Alternating Direction Implicit Method (ADI). The contents of the article indued: the establish of two-dimension tidal current equation, radioactive waste water pollutant dispersion equation and cooling water heat convection diffusion equation, the numerical difference calculation model of tidal current field, concentration field as well as temperature field, effect impingement with ADI method, numerical calcuation results.The result of research showed that: when the Dayawan Nuclear Power Station is on normal operation and after the low Level radioactive waste water and Low temperature cooling water have been drainde off into the sea, it is found that the radioactive concentration is near and enen Lower than the natural background radiation just outsite the area of about 4km² round the water outlet, the temperature difference is not obrious just outside the area of about 6 km² round the water outlet, the effect of impingement of abont 4.3%.