Abstract
The radiological risks following two severe hypothetical accidents at a proposed pressurized water reactor (PWR) in Umm Huwayd in the Eastern Coast of Saudi Arabia, have been determined using the health physics code HotSpot 3.1.2, developed by Lawrence Livermore National Laboratory, USA. In this paper the general plume dispersion code was used, the Total Effective Dose Equivalent (TEDE) were estimated and the direction of propagation was included the two accident scenarios for various stability classes A, B, C, D, E and F. At a closer distance to the release point the TEDE peaked faster for class A in both accident scenarios. The maximum TEDE values received by the NPP site workers, member of public and the permanent resident were estimated for both accident scenarios at a distance of 0.12 km, 4 km and 80 km from the released source point, respectively. For the two accident scenarios at two distances (0.10 km and 80 km) from the release point, the TEDE values were evaluated for different pathways (inhalation, submersion, ground shine and resuspension). The outcomes showed that for both scenarios, at 0,10 km, the submersion pathway is the dominant intake followed by inhalation and at 80 km distance, the most dominant pathway was found to be (inhalation) followed by (submersion). The effective release height of 10 m, 20, 30 m and 40 m was simulated and found to have inverse relation with TEDE and the ground deposition. Inversion layer height also was evaluated.