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Objective This study intends to analyze the radioactivity level of slag and its building materials, estimate the effective dose of the residents caused by the comprehensive utilization of slag in building materials, and provide basis for rational utilization of slag. Methods Data of slag production and its comprehensive utilization in building materials, radioactive level investigation and detection of slag and building materials in different periods and regions were collected from 2005 to 2016. Using the room model of concrete structure and the model of calculating equilibrium equivalent radon concentration with the specific activity of 226Ra in indoor building materials, the external and internal radiation doses of residents caused by comprehensive utilization of slag for building materials were estimated respectively, and then the annual additional effective dose and collective dose of residents were estimated. Results The contents of 226Ra and 232Th in the slag were relatively high, while the contents of 40K were relatively low. The radionuclide content in slag cement decreased significantly. The annual additional effective doses of slag used in concrete and cement mixture relative to ordinary cement were 0.40 mSv·a−1 and 0.20 mSv·a−1 respectively. The annual additional collective dose and 50-year collective dose caused by slag used in building materials were 3.87 × 103～1.84 × 104 man·Sv and 1.94 × 105～9.20 × 105 man·Sv respectively. Conclusion The comprehensive utilization of slag in building materials increases the additional effective dose of residents, so the use of some slag in building materials needs to be paid more attention to. In addition, the influence of comprehensive utilization of slag in building materials, such as the way, the amount of slag and the amount of building materials, on the annual additional effective dose of residents caused should also be paid attention to.
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Objective To understand the background level of total radioactivity in drinking water around Tianwan Nuclear Power Plant. Methods According to the original plan of the National Health and Family Planning Commission of China, the monitoring of gross α and gross β radioactivity levels in drinking water during dry and rain periods around Tianwan Nuclear Power Plant, and water samples were collected including source water, factory water, peripheral water and reservoir water. Results A gross of 200 water samples were monitored at 35 sampling sites from 2016 to 2018.The gross α and gross β radioactivity levels in the dry period were (0.038 ± 0.033) Bq/L and (0.11 ± 0.03) Bq/L. The gross α and gross β radioactivity levels in the wet period were (0.038 ± 0.024) Bq/L and (0.11 ± 0.03) Bq/L. There were statistically significant differences in gross α and gross β radioactivity levels between the source water and the other water during the dry season (P < 0.05). There were statistically significant differences in gross α and gross β radioactivity levels in different years (P < 0.05). There were statistically significant differences in gross α and gross β radioactivity levels at different distances from the nuclear power plant (P < 0.05). Conclusion The gross α level and gross β level of radioactivity in drinking water around Tianwan Nuclear Power Plant are in line with the standard of drinking water, regular, fixed and continuous monitoring should be carried out, and radionuclide monitoring and radiological investigation should be carried out on this basis.In view of the density of personnel in the vicinity of nuclear power plants in China, nuclear emergency preparedness training should also be strengthened.
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Objective@#To investigate the distribution of gross α and gross β radioactive levels in drinking raw water from different regions of Guangdong province, and to establish the radioactive level base line value in raw water.@*Methods@#The samples from 191 drinking water sources in use in Guangdong province were collected in rainy season and dry season, respectively, and determined and analyzed under the standard examination method for drinking water-radiological parameters (GB/T 5750.13-2006). The levels of gross α and gross β radioactivity were evaluated under the standard for drinking water quality (GB 5749-2006).@*Results@#A total of 377 raw water samples were taken, including 189 samples in rainy season and 188 samples in dry season, in which 186 samples were matched between rainy season and dry season. In dry season, the gross α levels ranged from 0.008 Bq/L to 0.582 Bq/L, averaged at (0.034±0.060) Bq/L, while the gross β levels ranged from 0.014 Bq/L to 0.637 Bq/L, averaged at (0.108±0.091) Bq/L. In rainy season, the gross α levels ranged from 0.008 Bq/L to 0.402 Bq/L, averaged at (0.045±0.064) Bq/L, while the gross β levels ranged from 0.014 Bq/Lto 0.848 Bq/L, averaged at (0.125±0.128) Bq/L. The gross α and gross β radioactivity levels of other samples were much lower than the guidance values in the national radioactivity standards on drinking water radioactivity, except for a sample from Shanwei area. The gross α and gross β radioactivity levels in the rainy season were higher than in the dry water season, and the gross α radioactivity levels in the rainy season were significantly higher than in the dry water season. There were significant differences in gross α and gross β radioactivity levels in rainy(Frainy season=1.819, 2.709, P<0.05) and dry season (Fdry season=1.985, 8.461, P<0.05)in different water systems, and the levels of gross α and gross β radioactivity in the rivers in western Guangdong were the highest. The gross α and gross β radioactivity levels of groundwater in rainy season were higher than in river water and lake water, and the gross α and gross β radioactivity levels in river water were higher than in lake and reservoir water, with the statistically significant differences(Ftotal α=39.323, Ftotal β=25.911, P<0.05), the gross α and gross β radioactivity levels in dry season were higher than in river water and lake water, with the statistically significant difference(Ftotal α=11.520, Ftotal β=28.435, P<0.05). The highest radioactivity levels is in groundwater, followed by river water, and the lowest is in lake and reservoir water.@*Conclusions@#The natural radioactivity background levels in drinking raw water in Guangdong province is lower than the limit value on drinking water stipulated by our country. The radioactivity levels in raw water in western Guangdong is significantly higher than in other water systems, and the radioactivity level in river water is also significantly higher than in lake and reservoir water.
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Objective To ascertain the background levels of total α and total β radioactivity in drinking water around Qianshan Nuclear Power Plant (QNPP). Methods Under the National Health and Wellness Committee′s program, 11 monitoring points within 30 km of QNPP were selected in Haiyan County in 2018. The samples of raw water, factory water and tap water were collected in the first half and the second half of the year, respectively, and determined and analyzed according to Standard Examination Methods for Drinking Water - Radiological Parameters (GB/T 5750.13-2006). The total α and total βlevels in the tested drinking water were evaluated under the Standards for Drinking Water Quality ( GB 5749-2006) . Results A total of 22 water samples were collected from 11 sampling points in April and September 2018, respectively. The residue rate obtained after drinking water was dried varied, dependent on different types of water, which could be up to 0.0337％. The total α levels in different types of water ranged from 0.008 to 0.04 Bq/L, averaged on (0.015±0.009) Bq/L, whereas the total β levels ranged from 0.014 to 0. 320 Bq/L with an average of ( 0. 188 ± 0. 068) Bq/L. There was statistically significant difference in totalαlevels between raw water and factory water ( Z=-2.286, P<0.05) , without statistically significant difference between residue rate and totalαand totalβlevels ( P>0.05) . The background levels of total α and total β radioactivity in 93 drinking water samples in 2016 and 2017 were also investigated, combined with a total of 115 water samples from different water bodies in 2018. There was statistically significant difference in total α and total β levels in tap water between 2017—2016 and 2018 ( Z=-2.976, -2.031, P<0.05), between 2016 and 2017 (Z=-2.042, -3.214, P<0.05) and between 2017 and 2018 (Z=-20. 112, -2.511, P<0.05). Conclusions The operation of nuclear power plant has no impact on radioactivity level in drinking water around QNPP. The drinking water around QNPP is safe.