Aircraft radiation exposure assessment in a radioactive environment: Ambient dose equivalents and effective doses

The release of radioactive plumes can occur due to nuclear power plant accidents, terrorist attacks, or scenarios in the chemical, biological, radiological, and nuclear defense (CBRN) field. Rescue aircraft may be exposed to ionizing radiation in such contaminated zones. Previous experimental assessments of these scenarios to estimate the potential dangers crew and passengers face are usually intangible. Using predictive software, it is possible to extract information from an external radiation field to which an aircraft would be subject. However, such codes cannot internally estimate the impact of this field on the aircraft. Using simulations based on the Monte Carlo method, it was possible to reproduce the scenario of plumes in the external environment (atmosphere) and, from this scenario, generate relevant information about their impact on the aircraft's internal environment. These assessments comprise the interaction of radiation from a radioactive plume with the aircraft structures and fuel tanks to estimate the radiation doses received by the crew and onboard electronics. This work evaluates the fluence rate, ambient dose equivalent rate (Ḣ*(10)), and effective dose rate (Ė) inside an aircraft flying through a radioactive plume resulting from a nuclear power plant accident. The simulation results suggest that radiation dose rates vary widely depending on the position within the aircraft. The ambient dose equivalent rate for photons varies by approximately 80% depending on the position within the aircraft. These differences reach around 98% for the ambient dose equivalent and effective dose rates for electrons. The data obtained may also be incorporated into risk assessments and support the development of protective measures to counter CBRN events.