RECONSTRUCTION, VERIFICATION AND ANALYSIS OF RESULTS OF WBC MEASUREMENTS DATED 1986 THAT WERE INPUTTED TO ELECTRONIC DATABASE IN 2019–2021

Objective of research is to improve the electronic database of WBC measurements dated 1986 by inputting of new information from paper carriers, reconstruction of information gaps, verification and analysis of new entered data, revision of internal exposure doses that are based on results of WBC measurements dated 1986. Materials and methods. In 2013–2015 during a revision of databases (DB) of WBC measurements results dated 1986–2014, it was discovered a great amount of paper carriers with information about WBC measurements, including the ones dated 1986, that were not inputted to the electronic DB. The paper carriers were systematized and ordered by the following indicators: place of residence of a person and place of WBC measurement, institution and operator that made the measurement, measurement device and date of measurement. For a comfortable inputting of the information to the electronic DB, it was additionally created a form which exists as an option in existing program complex Silbody (Version 19.0.9). In the revised DB of WBC measurements dated 1986 internal exposure doses from radio-cesium of Chornobyl origin were computed based on an ecological and dosimetric model for radio-cesium migration in environment and a model for radio-cesium metabolism in human body. In the work, mathematical and statistical methods of research were used. Results. In 2019–2021 additionally 35,319 notes were inputted to the electronic DB of WBC measurement dated 1986, and as a result its volume increased in 2.2 times. Mostly those are data on results concerning residents of Kyiv, Zhytomyr, Donetsk, Cherkasy, Odessa, Ivano-Frankivsk, and Rivne Oblasts. It was established the information on measurement devices and respectively on the minimal detected activity (MDA) for 27,119 notes (76.7 % of all new entered). Information is reconstructed about the body mass of all persons under investigation. Evaluation is made for values of intake of incorporated radionuclides 137Cs and 134Cs for all new entered to DB. Quality of reconstructed information was analyzed. To group 1, «qualitative», it was classified 18,598 notes (53 % of all new entered), measurements in 1986 (including new entered). Dose not exceeding 1 mSv was obtained by 80 % of adults (older than 20), as well as 73 % of persons younger than 20. Conclusion. To DB of WBC measurements, it was additionally inputted 35,319 notes on results of measurements dated 1986. New entered information is verified and distributed by the quality groups. Individual exposure doses evaluated based on those data can be used for further scientific research. Key words: database; whole body counter of exposure; results of WBC measurement; Chornobyl accident; internal exposure dose.

MCNP model of the EEAE ACCUSCAN Whole Body Counter

Monte Carlo simulations and verification measurements for the efficiency calibration of the ACCUSCAN shadow-shield type Whole Body Counter (WBC) of the Greek Atomic Energy Commission (EEAE) are presented. A model of the counter and RMC-II anthropomorphic phantom was developed using the MCNP code. Full energy peak efficiencies for different phantom positions were calculated for 60Co and 137Cs sources. The deviations between computational and experimental efficiencies were found to be less than 12 % for 60Co and 4 % for 137Cs for the Ge detector and less than 25 % for 60Co and 4 % for 137Cs for the NaI detector. This work contributes to the accurate quantification of internal contamination in individuals accidentally exposed in Greece by the Greek Atomic Energy Commission Laboratories and moreover demonstrates the effectiveness of using computational tools for understanding the calibration of radiation detection systems used for in vivo monitoring.