Windrose and Radinuclide Dispersion Modeling for Nuclear Malaysia Research Reactor

Transcription

1 Windrose and Radinuclide Dispersion Modeling for Nuclear Malaysia Research Reactor Dr Mohd Nahar Othman Malaysian Institute for Nuclear Technology Research (MINT) Bangi, KAJANG, MALAYSIA Abstract After the incident of radioactive gasses released to the environment because of unusual earthquake and tsunamis happen in Fukushima, Japan. The problem of release of radiological radionuclide became deep concern and serious problem to the world community. The incident course almost all nuclear power plant in Japan cannot operate because opposition from local people. From this point of view Malaysian Nuclear agency don't left behind in doing it research in release of radionuclide from it research reactor, in the meantime new wind rose data had been collected from 2013 to This paper will present the new radionuclide release including the new dispersion modelling that had been developed. 1.0 INTRODUCTION 1.1 A wind rose depicts the frequency of incidence of winds in each of the particular wind direction sectors and wind speed modules for a specified site and time period. The most regular structure consist of a circle from which eight or sixteen lines come out, one for each direction. The length of each line is comparative to the occurrence of wind from which direction and the occurrence of calm conditions is entered in the centre. 1.2 There are a lot of variations in the construction of wind roses. Some point out the range of wind speeds from each direction, and some indicate wind direction with other meteorological conditions. 1.3 The wind roses are widely applicable in the fields such as Environmental impact assessment, industrial emissions measurements, oceanography, wind energy, agriculture engineering, ambient air monitoring, air quality measurements, indoor air quality testing, air dispersion modelling, noise impact modelling and soil impact modelling. 2.0 METHODOLOGY 2.1 Construct and interpret data Wind rose may be constructed from the data obtained over a given time period such as a particular month or season or a year. In constructing or interpreting wind roses, it is necessary to keep in mind the meteorological convention that wind direction refers to the direction from which the wind is blowing. A line or bar extending to the north on the wind rose indicates the frequency of winds blowing from the north. The wind rose diagram is prepared using an appropriate scale to represent percentage frequencies of wind directions and appropriate index; lines to represent various wind speeds. A wind rose gives very concise but information-laden view of how wind speed and direction are usually spread at meticulous site. The wind roses revealed here have extra information, in that each spine is broken down into separate frequency categories that explain the percentage of time that winds blow from a meticulous direction and at definite speed ranges. All wind roses evolved here use basic directions, such as north (N), north-east (NE), East (E), South-East

2 (SE), South (S), South-west (SW), West (W), and north-west (NW). So, the software used to produce these highclass wind roses is consideration of Lakes Environmental Software and is said to be WR-PLOT. 2.2 Main Features Rapidly and simply visualize the wind rose for the given meteorological data. This is an outstanding method to precise huge amounts of wind data, and performs excellent declaration. However, rapidly evaluate the given meteorological data in a lot of ways that is by wind rose plots, frequency distribution tables and wind class frequency distribution graphs. Every general file formats are supported and for those that are not, an import from Excel utility allows simple importing. 2.3 Working Wind rose can read the data from files consists of data in columns; the majority of data-loggers accepted the output format. A minimum of five columns of data are essential to run the program which are wind speed, wind direction, hour, day, month, and year. With hour, day, month, and year many formats are accepted. If cloud cover, precipitation, cloud height, stability class, temperature, pressure and relative humidity are recorded, the suitable analysis is performed. 2.4 Input Data The essential parameters used by WRPLOT View comprise the following: Ex:- 1) Surface Station Number (the five-digit number) 2) Year 3) Month 4) Day 5) Hour (basis of 24-hour clock and is recorded as 00 to 23) 6) Wind Direction (from which direction the wind is blowing), East 090 South 180 West 270 North 360 Calm 000 7) Wind Speed (the wind speed measured in knots or m/s). 2.5 Dispersion Modelling using Generic Models These expressions are appropriate for dispersion over relatively flat terrain without pronounced hills or valleys. The terrain is assumed to be covered with pastures, forests and small villages. These assumptions are specified in the notes to that table given below (International Atomic Energy Agency, Vienna, 2001). This method is used for the assumption of dispersion radionuclide based on specified distance.

3 This approach clearly over estimates the concentrations near the source, but it is considered appropriate for screening purposes to ensure that actual doses are not underestimated by more than a factor of ten (International Atomic Energy Agency, Vienna, 2001). To find out more detail about this dispersion factor, refer to Table 3.1: Table 3.1: Dispersion Factor for Neutral Atmospheric Stratification No. Distance (m) Time Dispersion Factor sec m 40 sec m 20 sec m 40 sec m 20 sec m 40 sec m 20 sec h 6 m 40 sec h 23 m 20 sec h 5 m h 46 m 40 sec To calculate the concentration of the radionuclide that include Ar-41, I-131, and Co-60 is using by this formula: Where; CA = PpFQi/ua CA = concentration at soil level (wind direction) length x (Bq/m3) (estimate x= 100m) Pp = time average per year at where the wind blow (worst estimate, Pp = 1) F = Gaussian diffusion factor (m-2) which is the high of emission (estimate 30m) Qi = average rate of emission per year for nuclide (Bq/s) ua = average speed limit of wind at high emission (m/s) (given from SAR =1m/s) 3 RESULT AND DISCUSSION 3.1 This wind rose application can be observe through the result of Malaysian Nuclear Agency wind rose data from Jan-June 2014 and July-December Data from wind speed and wind direction had been manipulated that is wind rose data Jan-June 2014, and data July-Dec Table 2 and 3 below shows the frequency of the data. Table 2: Frequency of wind rose data from Jan June 2014 Direction For Tally Frequency % N NE E SE S SW W NW Total

4 Jan-Jun 2014 W NW N NE E Jan-June 2014 SW SE SE Table 3: Frequency of wind rose data from Jan Dec 2014 Direction For Tally Frequency % N NE E SE S SW W NW Total Jan - Dec 2014 W NW N NE E July - Dec 2014 SW SE SE

5 st Qtr 2nd Qtr 3rd Qtr 4th Qtr East West North Figure 3.4: Result on WR-PLOT view

6 Figure 3.5: Result on Google Earth 3.2 Ar-41, I-131 and Co-60 data released from the MNA stack had been collected from 2014 and the analysed of the data had been carried out and the result of the data as shown in Table 1. Table 1: Average concentration of Ar-41 (Noble gas), I-131 and Co-60 that had been released to environment from 2014 and it yearly dose received by the environment. Year Average concentration (Bq/m 3 ) Ar-41 I-131 Co-60 Yearly Dose (µsv/year) x x x Warning level 6.5 x Discharge limits 1.2 x 10 7 (SAR 2008) 1

7 i. Radiological model the movement of radionuclide in the morning for 2014 (12:00 a.m 9.00 a.m Figure 3.7: Result in the morning

8 ii.radiological model the movement of radionuclide in the afternoon for 2014 (9.00 a.m 3.00 p.m): Figure 3.8: Result in the afternoon iii.radiological model the movement of radionuclide in the evening for 2014 (3.00 p.m 7.00 p.m): Figure 3.9: Result in the evening

9 iv. Radiological model the movement of radionuclide in the night for 2014 (7.00 p.m 11 p.m): 4. CONCLUSION Figure 3.10: Result in the night ACKNOWLEDGEMENTS The authors wish to express their sincere thanks to Reactor Department of MNA for providing the data of radionuclide release to be included for this Paper. REFERENCES Journal Citation: Eary, J. F, Collins, C., Stabin, M. and Vernon, C., (1993), Samarium-153 EDTMP biodistribution dosimetry estimation, J. Nuc. Med. 34: Safety Reports Series 19, Generic Models for Use In Assessing the Impact of Discharges of Radioactive Substances to the Environment. International Atomic Energy Agency, 2001 Safety series No 115, International Basic Safety Standards for protection againts ionizing Radiation and for the safety of Radiation Sources. International Atomic Energy Agency, 1996 Book chapter: Stoll, B. A., (1983), Natural history, prognosis, and staging bone metastases. In: Bone Metastases: Monitoring and Treatment. B. A. Stoll and S. Pharbhoos (eds.). NY Raven Press, New York Book: Glasstone, S. and Sesonke, A., (1967), Nuclear Reactor Engineering. Van Mostrand Reinhaold Company, New York. 244 pp. Report: IAEA, (1975), Laboratory Manual on the Use of Radiotracer Techniques in Industry and Environmental Pollution. Tech. Rep. Series No. 161, Vienna, Austria.

10 Proceeding: Surif, S., Heng, P. H., Jelin, N. and Juzu, H. A., (1994), Preliminary study on some detoxication / toxication enzymes in fish in the Muda area. In: Proceeding of the Seminar on Impact of Pesticides on the Rice Agroecosytem in the Muda Area. B. M. Nashriyah, K. Y. Lum and B. S. Ismail (eds.) December 1994, Pulau Pinang Thesis and Dissertation: Nasir, A. I., (1980), The Use of Inhibitors in Water Cooling Systems. M.Sc. Thesis, University of Surrey, Pergerakan Angin Pada Tahun 2014 (Jan - Oktober) Gambaran Pergerakan Angin Pada Waktu Pagi JANUARI FEBRUARI MAC APRIL

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