Atmospheric dispersion database system WSPEEDI-DB; Quicker calculation of atmospheric dispersion of radioactive materials under various meteorological and release conditions

Terada, Hiroaki; Nagai, Haruyasu

Isotope News, (775), p.44 - 48, 2021/06

https://www.jrias.or.jp/books/cat3/2021/775.html

no abstracts in English

Analysis of meteorological observation data for the atmosphere diffusion calculation

; ; ; ; Kano, Yutaka

PNC TN8420 96-017, 50 Pages, 1996/08

PNC-TN8420-96-017.pdf:2.16MB

The meteorological observation has been performed since 1955 in PNC Tokai-works. After 1974, this observation came to measure on the top of the meteorological tower (100m above sea level) for the environmental assessment of a radioactive waste with the atmospheric discharge from the reprocessing plant. This report presents an atmospheric phenomenon statistic result and an examination about a characteristic of the atmosphere diffusion based on the data from 1977 to 1995. Characteristics of the result are as follows; (1)It was confirmed that the maximum air concentration point that was calculated based on the discharge amount from reprocessing plant and atmospheric phenomenon statistic of each year appears at near point in the safety assessment of 1977. (2)In some case, a maximum concentration point has appeared at about 800m in the west-southwest direction owing to the deference of appearance frequency of the atmospheric stability, etc. Normally it appears at about 2,000m point in south-west direction. Still, as reference materials, atmospheric phenomenon statistics result and relative concentration were mentioned.

None

Okubo, Hiroo*

PNC TJ1222 95-001, 48 Pages, 1995/02

PNC-TJ1222-95-001.pdf:0.87MB

None

Statistic analysis of meteorological data used for the dose estimation of the public around O-arai Engineering center, PNC

; Ishida, Junichiro; ; Takeishi, Minoru

PNC TN9450 91-006, 30 Pages, 1981/08

PNC-TN9450-91-006.pdf:0.67MB

Exposure of the public around O-arai Engineering Center (OEC) is estimated in two cases at the ordinary operation and at the postulated accidentsby using the observed meteorological data at OEC. The calculations are done based on the 'Meteorological Guide for Safety Analysis of Nuclear Power Plants' prepared by the Nuclear Safety Commission. According to the guide, the sum of the inverse of wind speed for every direction, atmospheric stability and so on should be used to calculate annual mean concentration of radioactive materials for dose estimation. Health and Safety Division in OEC has been observing wind speed, wind direction, insolation, net radiation and vertical temperature difference. These meteorological data from 1980 t0 1988 are reviewed statistically. The main conclusions of this study are as follows; (1)As the results of examination, the maximun deviation of the observation data at each year is 16 % from the average. The 16 % is within 30 % which is presented in 'Meteorological Guide for Safety Analysis of Nuclear Power Plants'. Therefore it is judged that there is no unusual data between 1980 and 1988. (2)The specific results on the data at 80 meters height are as follows; (a)Average of the most occurance frequencies of wind direction at each year is l8% for the wind from north east. (b)Range of the most occurance frequencies of wind speeds at each year is 5.0 5.9 m/s for the wind from north east. (c)The most occurance atmospheric stability for the wind from north east is D type, whose frequency is about 65%. (3)Average of 'the maximum of annual mean air concentration' around OEC is 4.7 10 Bq/cm, and average of 'the maximum effective dose equivalent is 6.910 Sv/Y, which are based on the caluculations by assuming the release of one Bq per year.