# Exercise #15

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• Problem #1 - In the previous dose calculation, we used a 5 km resolution concentration grid. Would the dose still be under-estimated if we used a finer concentration grid?

• Hint - Edit and run the cust_dose batch file to use a 1 km by 250 m grid resolution.

• Solution - 5 km air dose versus 1 km air dose
and 5 km deposition dose versus 1 km deposition dose,
shows a factor of 5 to 10 increase in dose close to the source. More distant doses are about the same. Note the squares of on or off wet deposition resulting from the half-degree resolution of the meteorological model.

• Problem #2 - There is some uncertainty regarding particle sizes for this event and a fraction of the radionuclides may have been emitted on much larger particles. Using the same configuration as in problem #1, recompute the doses using a deposition velocity of 1 cm/s rather than 0.1 cm/s.

• Hint - Edit the script cust_dose and rerun the calculation.

• Solution - Although the air dose is unchanged, the maximum deposition dose has almost doubled.