1 of 16

M. I. Chepurny, S. V. Masiuk, L. M. Kovgan����Reconstruction of individual �internal thyroid doses �due to Chornobyl accident exposure: ��the problems and solutions ��

2 of 16

�� Base material for reconstruction of thyroid exposure doses in Ukraine� due to Chornobyl disaster: �mass scale measurements of radioiodine content in the thyroid ��Period of measurements:�May-June of 1986� Organized:�by Ministry of health protection of Ukraine��Executing personnel:� mainly the staff of various medical institutions of Ukraine �� Advisory assistance�was provided by the team of specialists� from the Research Institute of Hygiene of Maritime Transport �(city of Leningrad) �Number of measurements:�circa 150 000

3 of 16

USAGE OF THE MEASUREMENTS�1986 Finding of the individuals with significant thyroid exposure �for providing of additional medical examinations Dose assessments of emergency nature (extremely conservative) ��1992-1997 �Thyrodosimetric passportization of Ukraine’s settlements �Conservative dose assessments��1998 – 2013 �Epidemiological studiesImproved dose assessments for selected persons;�first estimations of dose uncertainties 2014 – 2016 �Revised thyrodosimetric passportizationCorrection of doses estimations and their uncertainties �for all 150 000 of measured persons. �Calculation of realistic passport thyroid doses �for 30 000 settlements of Ukraine

4 of 16

Sources of uncertainty of dose estimation

Uncertainty of dose estimation

Uncertainty of direct thyroid measures

Uncertainty of data about individual behaviour

Uncertainty of parameters of ecological model

Fidelity of calculation procedure

5 of 16

Radioiodine content in thyroid depending of milk consumption

6 of 16

Influence of milk consumption on calculated thyroid dose �in case of direct thyroid measurement availability

7 of 16

Influence of relocation on calculated thyroid dose �in case of direct thyroid measurement availability

8 of 16

Important source of uncertainty in thyroid doses estimation – �uncertainty of the thyroid mass

9 of 16

10 of 16

11 of 16

Investigation of device sensitivity �to incorporated radiocesium

  • GTRM-01ts �is shown as example

12 of 16

13 of 16

Age correction factor values�for SRP-68-01 with different collimators

14 of 16

Proposed values of calibration factors for SRP-68-01 �in case of lack of the calibration data �(the values are compared with experimental data from Kaidanovsky, Dolgirev)

15 of 16

16 of 16

  • Thank you for your attention!