EVALUATION OF PROSPECTIVE DOSIMETRY FOR MEMBERS OF THE PUBLIC FOLLOWING THE FUKUSHIMA ACCIDENT

摘要

The contamination of land surrounding the Fukushima Daiichi Nuclear Power Plants has resulted in continued evacuation of many square kilometers of land area. The Japanese government has established a standard for evacuation of 20 mSv accumulated dose to a member of the population in the first year following the accident. In order to evaluate the areas chosen for evacuation and the level of protectiveness established by that standard, an analysis of the predicted dose accumulation is necessary. The magnitude of dose reduction due to time spent indoors will vary based upon the construction of the structure and the distribution of contamination. The dose distribution within living structures is calculated for wood, concrete, and glass structures of varying thickness through a MCNP5 radiation transport model and compared to the exterior dose rate above contaminated ground. Governments responding to accidental radiological release must still demarcate the land areas requiring short-term and long-term evacuation and/or other remediation efforts based upon assumptions that are sufficiently protective of the resident population. These calculations provide a more understandable and defensible basis upon which to make those determinations.