Atmospheric dispersion modeling and radiological environmental impact assessment for normal operation of a proposed pressurized water reactor in the eastern coast of Saudi Arabia

摘要

As a licensing requirement, constructing a new nuclear power plant (NPP) requires performing a radiological environmental impact assessment (REIA) which includes the study of the radioactive releases' effects on the surrounding environment and population. These discharges could be aerial: from chimneys (stacks), evaporation, erosion, re-suspension; or could be liquid discharges: into rivers, lakes, estuaries or coastal waters. This work presents an REIA study for a pressurized water reactor (PWR) assumed to be installed in Umm Huwayd in the Eastern Coast of Saudi Arabia. HYSPLIT tool is utilized to estimate the air concentration and ground deposition of certain released radionuclides such as: ~(137)Cs and ~(131)I. It is also used to analyze the exposure dose's spatial distribution around the nominated site according to direction and distance. The radionuclide dispersion profiles for each of the four weather seasons were examined. The results revealed that the radionuclides dispersion profile is controlled by the weather parameters that varies from season to season. Around the nominated site, Umm Huwayd, the maximum estimated air concentration for ~(131)I radionuclide was 5.6×10~(-6) Bq m~(-3), and the annual air deposition for ~(137)Cs at the selected site had a peak value of 3.3×10~(-9) Bq m~(-2). GENII is also utilized to estimate the annual effective dose equivalent and cancer risks around the nominated site. The ingestion pathway contributed to the most of annual effective dose equivalent with 68.35 of the total, while external exposure and inhalation pathways contributed 30.50 and 1.15, respectively. It is shown that in the nominated site the total annual rate of new cases of cancer (cancer incidence) is 1/10~9 persons. The cancer death annual rate (cancer fatality) is 5/10~(10) person. Therefore, the highest risk level around the selected site is much lower than the tolerable levels as suggested by the International Atomic Energy Agency (IAEA) and the International Commission on Radiological Protection (ICRP).