## 2 Materials and Methods  
This study uses radiological data on measured activity concentrations of source materials (NORM) and consumer products from the Nuclear Security Commission (NSSC) of South Korea. Minitab software tool was used to perform statistical analysis of the data of consumer products using normality test, and median values were selected for more statistical significance as presented in Table 2[30]. The upper limit values were also selected for the data of the source materials (NORM) for this study. However, the mass of \({}^{238}\)U, \({}^{232}\)Th, and \({}^{40}\)K in a consignment of consumer product and NORM was obtained by multiplying the specific radioactivity ratio of each radionuclide or isotope by the mass or capacity of the shipping container, which is 21 tons. Then, the specific radioactivity of each isotope was multiplied by its mass to obtain the radioactivity per shipping container for consumer product and NORM assignment. A similar approach was employed by [31] in the assessment of risk during radioactive material transport, where the radiation source term per cylinder was obtained by multiplying the radioactivity of each isotope in the feed, tails, and product by the capacities of the cylinder. Therefore, the radioactivity concentration per shipping container was used as an input to the RADTRAN 6 and MicroShield\({}^{\circledR}\) Pro version 12.11 computer codes for the dose and risk assessment and estimation of external dose rate. However, the external dose rate estimated by Microshield was used as input to the RADTRAN computer code as presented in Table 3. Physical data including distance or length of route segments/links, speed of vehicle, population density, fire accident probability, type of road, and traffic volume were also obtained from the previous literature and online sources [29; 30; 31; 32]. Table 3 presents the radiological input data of NORM and consumer products, Tables 4 and 5 present the physical parameters, which serve as input data to the RADTRAN computer code for dose and risk assessment during transport accidents. Table 6 presents radiological and physical input data used in MicroShield computer code for estimating the external dose rate at 1 m. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Link Name** & **Length (km)** & **Speed (km/hr)** & **Population** & **Traffic Density** & **Traffic Volume/hr** & **Accident Rate of Fire (Occurrence/km-car)** & **Default Fire Conditional** & **Road Type** \\  & & & **(Persons/km\({}^{2}\))** & **Volume/hr** & **Accident Rate of Fire** & **Default Fire** & **Default Fire** \\ \hline Link\_1 & 16.6 & 110 & 22,654 & 9461 & 6.58 \(\times 10^{-14}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_2 & 48.7 & 110 & 6906 & 8827 & 9.99 \(\times 10^{-14}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_3 & 30.9 & 110 & 328 & 5270 & 2.39 \(\times 10^{-13}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_4 & 46.5 & 110 & 4345 & 8872 & 2.30 \(\times 10^{-13}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_5 & 22.9 & 110 & 4345 & 7321 & 1.12 \(\times 10^{-13}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_6 & 32.5 & 110 & 3024 & 11,877 & 4.32 \(\times 10^{-14}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_7 & 35.7 & 110 & 100 & 4345 & 6.14 \(\times 10^{-14}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_8 & 30.3 & 110 & 136 & 4472 & 5.28 \(\times 10^{-14}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_9 & 32.4 & 110 & 686 & 15,983 & 1.10 \(\times 10^{-13}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_10 & 37.3 & 110 & 4813 & 25,180 & 7.89 \(\times 10^{-14}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_11 & 45 & 110 & 614 & 5799 & 1.00 \(\times 10^{-13}\) & 6.3 \(\times 10^{-3}\) & Highway \\ Link\_12 & 37 & 80 & 204 & 1423 & 3.03 \(\times 10^{-12}\) & 6.3 \(\times 10^{-3}\) & Secondary \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Physical input data used in RADTRAN code for assessment of population/collective dose and risk [29; 32; 33].