ON THE METHODOLOGY OF PASSPORT DOSES CALCULATION FOR UKRAINIAN SETTLEMENTS RADIOACTIVELY CONTAMINATED DUE TO THE...

Area of Science:

• Environmental Science
• Radiological Protection
• Nuclear Safety

Background:

• Chernobyl Nuclear Power Plant accident impacts persist, necessitating ongoing radiation monitoring and control measures in affected Ukrainian territories.
• Previous methodologies for estimating settlement passport doses are outdated and do not reflect current scientific understanding of radioactive contamination.
• Cesium-137 (137Cs) remains the primary radionuclide of concern for long-term external and internal exposure assessments in contaminated areas.

Purpose of the Study:

• To scientifically substantiate a new methodology (Methodology-2023) for calculating passport doses in Ukrainian settlements within resettlement zones.
• To update the dosimetric passportization framework in accordance with current Ukrainian legislation and scientific advancements.
• To provide a more accurate assessment of radiation exposure for populations in areas affected by the Chernobyl disaster.

Main Methods:

• Developed a new model for calculating passport doses, incorporating parameters derived from radio-ecological and dosimetric monitoring data (1986-2013).
• Focused external exposure dose reconstruction on 137Cs, as other Chernobyl radionuclides have minimal impact years after the accident.
• Calculated internal exposure dose based on 137Cs in food products, prioritizing whole-body counter (WBC) measurements and 137Cs activity in milk.

Main Results:

• The Methodology-2023 resulted in an average 40% increase in passport doses compared to Methodology-96.
• Internal radiation doses increased by 1.5 times, and external radiation doses by 1.7 times under the new methodology.
• In 2011, 71 settlements exceeded the 1 mSv legal limit, primarily in Korostenkyi raion, Zhytomyr Oblast, when assessed with Methodology-2023.

Conclusions:

• Methodology-2023 provides a scientifically substantiated and more accurate estimation of passport doses for Ukrainian settlements.
• The updated methodology highlights a significant underestimation of radiation risks by the previous Methodology-96.
• The findings underscore the continued need for stringent radiation monitoring and protective measures in specific Ukrainian regions affected by the Chernobyl accident.