The biggest threat to national security is the use of radiological dispersion devices (RDDs) in terrorist attacks. Known as a dirty bomb, RDD is an explosive device combined with radioactive material. In addition to posing an immediate risk to people's lives and property, the explosion contaminates a large area with radioactivity. Decontamination is expensive and time-consuming. limited radiation exposure may result in long-term health issues, psychological issues, and social repercussions. Depending on the kind of radioactive material used and how well it is dispersed, an RDD can have different effects. This work aims to assess the radiological risk resulting from direct exposure to radiation sources used in radiation dose distributions as well as related legal issues. Using the Hot-spot computer code, simulations were run for radiation sources of 137Cs and 90Sr. To simulate radiological effects and ground deposition, calculations for radioactive material dispersion models are being carried out, considering the worst-case scenario. The parameters for ground surface deposition, ground shine dose rate, and total effective dose equivalent change as one gets farther away from the radiation source. Examined are the effects of variables like location, wind speed, radiological risk, and emergency response. There have been comparisons made between the radioactive material dispersion model and the considered radiation sources. Legal issues are also deliberated within the context of both national framework and international law.