海阳核电站周围居民饮用水中锶-90放射性水平调查与卫生学评价

Investigation and Analysis of Strontium Concentration of Drinking-water Surrounding Haiyang Nuclear Power Plant

目的调查海阳核电站周围居民饮用水中锶-90的活度浓度,分析枯水期和丰水期的放射性水平的变化规律,评价周围居民由饮水所致待积有效剂量。方法海阳核电站周围30 km内,选择10个采样点,每年按丰水期及枯水期分别采集样品2次,两年共8次,共计样品87个。样品预处理和制备采用国家标准(GB 12375-90)方法,使用FJ2603G低本底β测量仪测量。结果饮用水中锶-90活度浓度均值为(4.96±1.6)mBq·L-1,范围为1.21~9.12mBq·L-1。经配对t检验,发现海阳核电站周围饮用水中锶-90在枯水期与丰水期放射性水平差异无统计学意义(P>0.05)。各类水体锶-90活度浓度从大到小,枯水期依次为自来水>水井水>地表水,而丰水期依次为水井水>自来水>地表水。其所致居民待积有效剂量顺序为水井水>自来水>地表水,分别为0.104、0.103、0.095μSv·a-1。结论海洋核电站周围居民饮用水中锶-90活度浓度处于本底水平;周围居民饮水所致待积有效剂量远低于《电离辐射防护与辐射防护安全基本标准》(GB 18871-2002)所规定的限值(1 mSv),因此居民所受剂量为本底水平。

Objective To investigate strontium concentrations of Drinking-water surrounding Haiyang nuclear powerplant,and make a analysis of the influencial factors of the strontium concentration; to assess the accumulated-effective dose of the residents surrounding nuclear power plant. Methods We choose 10 sample points,including surface water、groundwater and drinking water within 30 km surrounding Haiyang nuclear power plant in wet period and dry period,collecting 87 samples for all. The pretreatment and preparation of samples referred to the recommended methods of the national standards( GB 12375-90). The FJ2603G low background liquid β-spectrometer is used to measure the strontium concentration. Results The average level of the strontium concentration of water samples was( 4. 96 ± 1. 6) mBq·L-1,the range of the strontium concentrations was from 1. 21 ~ 9. 12 mBq·L-1. The difference of the strontium concentrations between two different periods analyzed by the paired t-test was considered non-statistically significant( P > 0. 05). The orders of the average strontium concentration of various hydrographic period from high to low in drought period: tap water > ground water > surface water,as groundwater > tap water > surface water in high flow period. The accumulated-effective doses of groundwater、tap water、surface water which surrounding nuclear power plant were 0. 104、0. 103、0. 095 μSv·a-1,respectively. Conclusion The activity concentration of strontium in the drinking-water surrounding Haiyang nuclear power plant was at the lower level than that of others';according to the limited value that is regulated by basic standards for protection against ionizing radiation and fo the safety of radiation sources( GB 18871-2002)( 1 mSv),the accumulated-effective dose which residents suffered was in background level of radiation.