RESUMO
Objective To analyze the radionuclide levels in food and the committed effective dose due to food intake in residents around the Shidaowan Nuclear Power Plant (SNPP). Methods Daily food samples were collected within 30 km radius around the nuclear power plant in 2019—2022. The radioactivity levels before and after the operation of SNPP were determined. The data were combined with the dietary consumption of residents in Shandong province, China to estimate the committed effective dose. Results The radionuclides 238U, 232Th, 226Ra, and 40K in food were at normal background levels, and the average radioactivity was (0.062 ± 0.004), (0.121 ± 0.007), (0.162 ± 0.010), and (92.4 ± 5.5) Bq/kg fresh weight. Trace 137Cs and 90Sr were detected in some food samples and the average radioactivity was (0.047 ± 0.003) and (0.193 ± 0.200) Bq/kg fresh weight. The levels of radionuclides did not increase after the operation of SNPP compared with that before operation. The estimated committed effective dose in residents due to food intake was 0.205 mSv. Conclusion The radioactivity of food in the area around SNPP shows no difference before and after operation, and the dose burden is low in local residents.
RESUMO
Objective To investigate the gross alpha and gross beta radioactivity levels in drinking water around Shidao Bay Nuclear Power Plant before its operation. Methods Ten sampling sites were set up within 30 km of Shidao Bay Nuclear Power Plant. From 2018 to 2021, samples were collected during the dry season and wet season each year and were tested in a laboratory according to Standard examination methods for drinking water—radiological parameters (GB/T 5750.13—2006). Results From 2018 to 2021, the gross alpha radioactivity in drinking water within 30 km of Shidao Bay Nuclear Power Plant was within the range of about 0.004-0.420 Bq/L, which does not exceed the guided gross alpha radioactivity specified in the National Standard; from 2018 to 2021, the gross beta radioactivity level was about 0.008-1.050 Bq/L. In 2018, the gross beta radioactivity at the sampling site 4.7 km from the Nuclear Power Plant exceeded the guided level specified in the National Standards for Drinking Water Quality (GB 5749—2006), but it fell within the guided level in a repeat laboratory test after deducting the effect of 40K on the gross beta radioactivity. Conclusion After deducting the effect of 40K on the gross beta radioactivity, the gross alpha and gross beta radioactivity levels in drinking water within 30 km of Shidao Bay Nuclear Power Plant are within the guided levels specified in the National Standards.
RESUMO
Objective:To summarize the levels of individual dose to radiation workers in Shandong province from 2016 to 2020, and to analyze the trends in their change in order to provide scientific basis for radiation workers′ health management.Methods:The experimental detection and quality control were carried out in compliance with the national standards Specifications for individual monitoring of occupational external exposure (GBZ 128-2019) and the Testing criteria of personnel dosimetry performance for external exposure (GBZ 207-2016). The result of the personal dose monitoring of occupational external exposure of all radiation workers monitored by the Centers for Disease Control and Prevention in 16 cities of Shandong province were retrospectively analyzed by using SPSS 23.0 software.Results:The total number of monitored workers were 25 523 with an average annual individual effective dose of 0.28 mSv. There were statistically significant differences among radiation workers in different years ( H= 2 815.91, P<0. 001). The average annual individual effective dose showed an upward trend followed by a downward trend. The average annual effective dose of 0.55 mSv for nuclear medicine radiation workers in medical applications was the highest, with statistically significant differences among different occupational radiation workers ( H=310.37, P<0.001). The average annual effective dose of 0.37 mSv for radioactivity logging workers in industrial applications was the highest, with statistically significant differences among different occupational radiation workers ( H=448.07, P<0. 001). The average annual effective dose to radiation workers in medical applications was higher than in industrial applications ( Z = -14.93, P<0.001). Conclusions:The average annual effective dose to nuclear medicine radiation workers in medical applications and logging radiation workers in industrial applications are relatively high. There would be a push to furthe improve workplace protection measures and strengthen the management and supervision of radiological workers.