## 3 Results  
In this scenario, we assumed that no meat and milk obtained from the site would be consumed and that the water used for drinking would come from a non-contaminated source. External irradiation and inhalation pathways were considered. The external pathway was used in this study because one of the NORM used was potassium 40, which emits both beta particles and gamma rays that humans are exposed to externally. Uranium and thorium are alpha emitters and lack the energy to penetrate even the outer layer of the skin, and therefore external exposure is not the main concern; however, they can be fatal when inside the body. The input values used in RESRAD codes are shown in Table 4.  
Figure 4 shows the results for RESRAD-ONSITE for a resident scenario with AC below and above 1 Bq/g. In this scenario, we calculated the total dose (mSv/y) obtained from RESRAD-ONSITE with AC ranges below and above 1 Bq/g for an onset site resident who settles on a former landfill site contaminated with CPs containing NORMs. The pathways considered were inhalation and external exposure pathways using a modeling period of 40 years. The radiological dose rate for ACs above 1 Bq/g, as indicated by the orange values, was high, with a maximum value of 2.30E + 01 mSv/y. This was due to the high AC that is caused by the inhalation of radon and thoron decay products with little contribution to the external pathway from the decay of \({}^{40}\)K. The radiological dose for AC below 1 Bq/g, indicated by the blue line, shows that the values were all below the ICRP-recommended public dose limit of 1 mSv/y, with a maximum value of 8.80E-01 mSv/y because of the low AC considered in the simulation. Figure 5 shows the total dose rate (mSv/y) obtained from the RESRAD-OFFSITE scenario with AC ranges below and above 1 Bq/g. In this scenario, the offsite resident \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Codes** & **Models** & **Advantage** & **Disadvantage** \\ \hline RESRAD-ONSITE & Gaussian plume model & Evaluates radiological dose and risk to ensit receptors & Low wind speed condition, no memories of previous emission \\ RESRAD-OFFSITE & Gaussian plume model & Evaluates radiological dose and risk to offsite receptors & Breaks down during low wind speed condition \\ HotSpot & Atmospheric dispersion & Evaluates incident involving radioactive materials & Estimate the short range (less than 10 km) \\ NORMALYZA & Gaussian plume model & Simulate radionuclide transport from contaminated land to relevant receptors & Low wind speed condition, no memories of previous emission \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of models used in this study. Figure 4: Results from RESRAD ONSITE scenario. was assumed to live within the vicinity of a landfill site but does not eat or drink water from the contaminated site. The only exposure pathway considered in this scenario was the inhalation of radon and thoron decay products of NORMs over a 40-year modeling period. The total dose for both categories of AC is below the ICRP-recommended public dose limit of 1 mSv/y, with the highest dose of 5.28e-03 mSv/y for AC below 1 Bq/g and 0.132 mSv/y for AC above 1 Bq/g, respectively. These results show that it is safe for people to reside within a vicinity of a landfill site as offsite residents. Figure 5: Dose from the RESRAD-OFFSETITE scenario.