Health and safety plan for the Molten Salt Reactor Experiment remediation project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Unmanned air/ground vehicle survey following a radiological dispersal event

“…The area of the field surveyed by the drone is 17,500 m 2 , so given 35 GBq of material, that would give a uniform field of 2 MBq/m 2 . From Table A‐1 of Eckerman (2012), we know that the effective dose for $${}^{140}$$La is $$2.15\times 1{0}^{-15}\unicode{x0200A}\mathrm{Sv}/{\rm{s}}$$ per unit of ground surface activity, given in Bq/m 2 . Multiplying this by our value, and then by time, we get an estimated best‐case exposure of approximately 13 μSv of dose for a person while a UAV dose would be negligible.…”

“…A toy model can compare the exposure of a person to an unmanned air vehicle (UAV) by taking the distance traveled by the UAV and comparing it to the distance traveled by a person, assuming an even distribution of radiation throughout the whole area. Although not perfectly accurate, integrating the total flux over the time is accurate as an approximation, and we can use the tools from “Radiation dose and health risk estimation: technical basis for the state‐of‐the‐art reactor consequence analysis project” (Eckerman, 2012) to calculate a reasonable exposed dose for a dispersed source. It would take a human approximately 52 min to survey the same distance the UAV covered considering an average human walking speed of 5 km/h (Rose & Gamble, 1994).…”