Volcanic Ash Fall Hazard of Mount Merapi on Yogyakarta Nuclear Area

The existence of nuclear installations in the Yogyakarta Nuclear Area is vulnerable to eruption Mount Merapi, most active volcano Indonesia. Tephra hazard has potential threaten operational activities Area; thus, it necessary analyze distribution and volcanic ash from Merapi for future eruptions. Numerical modelling used analyzing tephra using TEPHRA2 software with parameters 2010 eruption, which then visualized isomass isopach maps distribution. analysis resulted dispersion leading April, May, June, August an accumulated mass 20-50 kg/m3 a thickness 0.2-12 cm. It deal hazards such as roof strength, secondary cooling system, filtering electrical system several Area.