Abstract:
Objective To monitor the gamma radiation dose in terrestrial environment near the Sanmen Nuclear Power Plant prior and posterior to its commercial debut,determine the background level,short-term and long-term trends,and evaluate its effects on nearby residents.
Methods A monitoring protocol for the gamma radiation dose in terrestrial environment near the nuclear power plant was developed according to the relevant national standards.Thirteen villages in seven towns of County N and six villages in two towns of Count X were selected as the monitoring sites,all in the prefecture of Ningbo and proximity to the nuclear power plant.Gamma radiation dose rate was measured by cumulative thermoluminescence dosimetry using three months as basic time scale,four times a year.The data collection work was done in the period from July 2011 to June 2013.
Results The data were classified into two groups:field and indoor data.The results of ANOVA showed no seasonal difference in the gamma radiation doses from field or from indoor (for 2011,field:F=0.452,P=0.716;indoor:F=0.442,P=0.723;for 2012,field:F=0.345,P=0.793;indoor:F=0.261,P=0.853).The annual effective dose per capita was 0.87 mSv.
Conclusion The gamma radiation dose rate in terrestrial environment near the Sanmen Nuclear Power Plant is at a normal level.This paper provides a background level of the gamma radiation dose before the plant's commercial debut as reference for further radiation surveillance program design.