ON THE METHODOLOGY OF PASSPORT DOSES CALCULATION FOR UKRAINIAN SETTLEMENTS RADIOACTIVELY CONTAMINATED DUE TO THE CHORNOBYL NPP ACCIDENT. / ЩОДО МЕТОДИКИ РОЗРАХУНКУ ПАСПОРТНИХ ДОЗ НАСЕЛЕНИХ ПУНКТІВ УКРАЇНИ, ЯКІ ЗАЗНАЛИ РАДІОАКТИВНОГО ЗАБРУДНЕННЯ В РЕЗУЛЬТАТІ АВАРІЇ НА ЧАЕС.

OBJECTIVE: scientific substantiation of the new methodology for estimation of passport doses of the settlementswhich belong to Zone of Unconditional (obligatory) Resettlement, or 2nd zone and Zone of Granted VoluntaryResettlement, or 3rd zone in the framework of dosimetric passportization in accordance with the legislation ofUkraine. MATERIALS AND METHODS: 37 years after the accident, radioactive contamination of the environment has significantly decreased. However, it is still necessary to carry out ecological and dosimetric monitoring and apply countermeasures in certain territories of Ukraine affected by the accident at the Chornobyl Nuclear Power Plant: restriction of the consumption of locally produced milk, forest products, etc. The methodology, which was since 1996 used to estimate the passport doses of Ukrainian settlements, no longer corresponds to the current level of scientific knowledge about radioactive contamination of environment. The new methods of passport doses calculating presented in the work involves the use of a model whose parameters are determined by the types, quality and completeness of radio-ecological and dosimetric monitoring carried out on the radioactively contaminated territories in 1986-2013. The methodology takes into account the specific of radioactive contamination of each settlement. The passport dose of external exposure is reconstructed only from 137Cs radionuclide, because the contributions of other Chornobyl radionuclides influence the radiation dose only in the first years after the accident. The passport dose of internal exposure is formed as a result of the consumption of 137Cs contaminated food products. It is calculated depending on the availability in the settlement in the current year of the results of measurements of the 137Cs radionuclide activity incorporated in the human body using a whole body counter (WBC) and the activity of 137Cs in the private milk. At the same time, priority is given precisely to the results of WBC measurements of 137Cs. RESULTS AND CONCLUSIONS: A new methodology (Methodology-2023) for passport doses calculation of Ukrainian settlements was substantiated. A comparison of passport doses based on the results of radioecological and dosimetric monitoring in 2011 calculated by Methodology-2023 and passport doses calculated by Methodology-96 was made.Passport doses calculated by Methodology-2023 increased by 40 % on average compared to doses calculated by Methodology-96. At the same time, passport doses of internal radiation calculated by the new methodologyincreased by 1.5 times, and passport doses of external radiation increased by 1.7 times. The passport dose of 2011, calculated by Methodology-2023, exceeds the legally established limit of 1 mSv in 71 settlements, most of which are located in Korostenkyi raion of Zhytomyr Oblast.

RECONSTRUCTION, VERIFICATION AND ANALYSIS OF RESULTS OF WBC MEASUREMENTS DATED 1986 THAT WERE INPUTTED TO ELECTRONIC DATABASE IN 2019-2021. / VIDNOVLENNIa, VERYFIKATsIIa TA ANALIZ REZUL'TATIV LVL/VYMIRIuVAN' 1986 R., ShchO VNESENI DO ELEKTRONNOÏ BAZY U 2019­2021 rr.

Objective of research is to improve the electronic database of WBC measurements dated 1986 by inputting of newinformation 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 dated1986-2014, it was discovered a great amount of paper carriers with information about WBC measurements, includ-ing the ones dated 1986, that were not inputted to the electronic DB. The paper carriers were systematized andordered by the following indicators: place of residence of a person and place of WBC measurement, institution andoperator that made the measurement, measurement device and date of measurement. For a comfortable inputtingof 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 dosesfrom radio-cesium of Chornobyl origin were computed based on an ecological and dosimetric model for radio-cesiummigration in environment and a model for radio-cesium metabolism in human body. In the work, mathematical andstatistical methods of research were used. RESULTS: In 2019-2021 additionally 35,319 notes were inputted to the electronic DB of WBC measurement dated1986, 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 onmeasurement devices and respectively on the minimal detected activity (MDA) for 27,119 notes (76.7 % of all newentered). Information is reconstructed about the body mass of all persons under investigation. Evaluation is madefor values of intake of incorporated radionuclides 137Cs and 134Cs for all new entered to DB. Quality of reconstructedinformation was analyzed. To group 1, «qualitative¼, 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 than20), 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 measurementsdated 1986. New entered information is verified and distributed by the quality groups. Individual exposure dosesevaluated based on those data can be used for further scientific research.

RESULTS OF WBC MEASUREMENTS WERE MADE AT RADIOACTIVELY CONTAMINATED TERRITORIES OF UKRAINE IN 1986-2014 (REVISION AND ANALYSIS). / REZUL'TATY LVL6VYMIRIuVAN', PROVEDENYKh NA RADIOAKTYVNO ZABRUDNENYKh TERYTORIIaKh UKRAÏNY U 1986-2014 rr. (REVIZIIa TA ANALIZ).

OBJECTIVE: revision, analysis, and significant improvement of quality of the database of WBC measurements made in1986-2014 at radioactively contaminated territories of Ukraine by the use of renewal of informational gaps andimprovement of the model for assessment of internal exposure doses. MATERIALS AND METHODS: Inthe periodfrom 1986 to 2014 experts of the Whole Body Counters Laboratory of NRCRMaccumulated about 1.5 million results of WBC measurementsof radio-cesium incorporated in the body of personsresiding at the territories which are radioactively contaminated due to Chornobyl accident. Most of measurements(~64 %) were made during the first 15 years after the accident. The most of measurements were made in Kyiv (~23 %),Zhytomyr (~36 %), Rivne (~20 %) and Chernihiv (~5 %) Oblasts. Works on revision of database of WBC measurementsincluded: transformation of data saved in paper format into electronic form, checking for correctness and correspon-dence of information, renewal of lacking information at the fields of database, improvement of the model for eval-uation of internal exposure doses by the data of WBC measurements. In the model for evaluation of revised doses,it is assumed uniform content of radio-cesium during a year. Reference values are used of metabolism parametersand anthropometric human parameters recommended in publications of ICRP. RESULTS: Revised doses have been reconstructed for 1,386,585 records of data base of WBC measurements that fitspecially elaborated criterions for estimation of quality of results. Among them 604,215 records are WBC measure-ments of children and adolescents younger than 18, and 782,370 records correspond to adult inhabitants of Ukraine,most of which reside in Zhytomyr, Kyiv, Rivne and Chenihiv Oblasts. CONCLUSIONS: Obtained results serve as a ground for further works on improvement of models for evaluation of pass-port doses and individualized exposure doses of subjects registered in Ukrainian State Register - of persons thataffected due to Chornobyl accident. Evaluated doses can be used for epidemiological, clinical and other research.

Reconstruction of individualized doses of subjects from the Ukrainian State Register - of Persons that Affected due to Chornobyl accident and reside in Korosten raion of Zhytomyr oblast. / REKONSTRUKTsIIa INDYVIDUALIZOVANYKh DOZ SUB'IeKTIV DERZhAVNOGO REIeSTRU UKRAÏNY OSIB, IaKI POSTRAZhDALY VNASLIDOK ChORNOBYL'S'KOÏ KATASTROFY, ShchO PROZhYVAIuT' V KOROSTENS'KOMU RAY̆ONI ZhYTOMYRS'KOÏ OBLASTI.

STUDY OBJECTIVE: To elaborate an ecological dosimetric model of reconstruction individualized exposure doses of subjects from the State Register of Ukraine (SRU) - of persons, affected due to Chornobyl accident and reside at the radioactive contaminated territory of Korosten raion of Zhytomyr Oblast, and to calculate exposure doses for those persons. MATERIALS AND METHODS: In the paper, an ecological dosimetric model is presented which is elaborated in order to individualize exposure doses of people who reside in Korosten raion of Zhytomyr Oblast and are registered in SRU. The model is based on the results of radio ecological and dosimetric monitoring held in the period of 1986-2013 at the territory of northern oblasts of Ukraine. Annual dose over each post accidental year consists of the two compo nents: (a) annual effective dose of external gamma exposure (due to radioactive fallout on the ground), and (b) internal exposure of the whole body (due to consumption of meal contaminated by radioactive isotopes). For 1986, the dose of internal exposure is evaluated out of all main radionuclides of radioactive accidental fallout, and after 1987 only for radioisotopes of caesium (134Cs and 137Cs). The parameterization of the model is based on the pre vious experience in working out a complex of ecological dosimetric models for estimation of referent exposure doses of Ukrainian population. RESULTS AND CONCLUSIONS: Individualized doses of external and internal exposure (annual and accumulated) are estimated for the population of various age groups that resides in the settlements of Korosten raion (totally about 100 settlements). Separately the doses are presented for rural settlements of the raion and for the city of Korosten for each year of the post accidental period of 1986-2016. Estimates of doses are given that were accumulated: (a) during 15 years just after the accident, (b) for the period of 2000-2016, and (c) for 30 year period after the acci dent. Mean dose accumulated for 30 years after the Chornobyl accident by residents of rural settlements of Korosten raion is estimated as 19.8 mSv, and for inhabitants of the Korosten city as 20.9 mSv. On condition of permanent res idence in the raion, residents of about 66 % settlements of Korosten raion accumulated the doses in the interval 5 20 mSv during 30 years after the accident. For the residents of about 25 % settlements the accumulated dose is in the interval 20-50 mSv, and for 7 % of settlements it exceeds 50 mSv.

Generalized results of individualized exposure doses reconstruction for the subjects of Ukrainian State Register of persons, affected due to Chernobyl accident. / UZAGAL'NENI REZUL'TATY REKONSTRUKTsIi INDYVIDUALIZOVANYKh DOZ SUB'IeKTIV DERZhAVNOGO REIeSTRU UKRAiNY OSIB, IaKI POSTRAZhDALY VNASLIDOK ChORNOBYL'S'KOi KATASTROFY.

Since 2007, the department of dosimetry of NRCRM has been working for to supply the Ukrainian State Register (SRU) of persons affected due to Chernobyl accident by exposure doses estimations. As of now, the individualization of doses has been performed for nine raions located in Kyiv, Zhytomyr, Rivne and Chernihiv oblasts. The structure of raion-specific models used for the reconstruction of individualized doses was described in detail in the previous 19-th issue of this journal (2014). The choice conditions for persons from the SRU using which for each raion there was formed a contingent of persons for whom the dose could be reconstructed. During the period of 2007-2015, the individualized dose was reconstructed for 244226 persons in 9 raions, representing ~ 58% of all registered in the SRU inhabitants of the raions. The calculation results were transferred to the SRU in formats adapted to the common database structure of the SRU. For each person who satisfied the conditions of selection there were estimated: (1) possible absorbed internal exposure dose of the thyroid by radioiodine in 1986 (assuming that the person in 1986 lived in the same village and was enlisted in the SRU); (2) annual doses of external, internal and total exposure of the whole body for a period of observation in the SRU; (3) total exposure dose of whole body accumulated during the period of observation in the SRU; (4) the total cumulative dose of feasible exposure during the period since 1986 till the decision to be registered in the SRU. There are presented the generalized results of the SRU subjects distribution for different raions in dependence on intervals of doses accumulated at different periods after the accident. The raion matrix tables show the dynamics of accumulation of doses by the SRU subjects both for their stay on the account and for the period of their possible residence registration in the settlement since 1986. The directions for further research to be implemented for increasing the number of persons for whom it is possible to calculate individualized dose have been formulated.

Basic Principles and Practices of Integrated Dosimetric Passportization of the Settlements in Ukraine. / OSNOVNI PRYNTsYPY TA DOSVID PROVEDENNIa KOMPLEKSNOi DOZYMETRYChNOi PASPORTYZATsIi NASELENYKh PUNKTIV UKRAiNY.

OBJECTIVE: The purpose of the review is to demonstrate the results of dosimetric passportization (performed in 1991-2014) for the settlements of Ukraine which suffered from radioactive contamination caused by the Chornobyl accident. The dosimetric passportization played a key role in the National program on the liquidation of aftermath of the Chornobyl accident directed on recovery through all stages of the current radiation situation control and decision support touching upon various types of interventions and social benefits to the population of radioactively contaminated areas. The works being performed under dosimetric passportization did not have analogues among the researches which took place after other large-scale industrial and municipal accidents as well their scales as the duration of both radio-ecological and dosimetric monitoring.The new methodological approaches to the assessment of so-called passport doses of a settlement as well as to the definition of the concept of annual dose being the dose used to make decisions for providing both direct and indirect emergency countermeasures for the settlements of Ukraine became pioneering ones. During all the post-accident period there were issued sixteen collections of general dosimetric passportization data which accumulate the results of hundreds of thousands spectrometric, radiochemical and radiation levels measurements and WBC measurements carried out in 1991-2014.The annual passport doses calculated on the basis of these measurements (including their components) are unique information that quantifies the level and time dynamics of the radiation situation for each of the 2161 settlements of 74 raions in 12 oblasts during all the post-accident period. Thanks to the works of dosimetric passportization of the settlements of Ukraine there were created databases to be unique in their structure and content with quantitative characteristics of the territorial and temporal distribution, the dynamics of changes of a number of important radiological parameters, namely over 500 thousands of measurements of concentration of 137Cs and 90Sr in the local foodstuff (milk and potatoes); there are more than 1.3 million of measurements of the cesium content in the body of residents of the settlements of Ukraine; there are 100 thousands of dose estimates (both internal and external ones were measured separately) of inhabitants living on the radioactively contaminated areas. The results of the dosimetric passportization served as one of the main exposure criteria for generalized aftermath of the Chornobyl accident represented in the National reports for the first 15, 20 and 25 years after the accident.

Interpretation of results of radioiodine measurements in thyroid for residents of Ukraine (1986). / INTERPRETATsIIa REZUL'TATIV VYMIRIuVAN' VMISTU RADIOiODU U ShchYTOPODIBNIi ZALOZI MEShKANTsIV UKRAiNY (1986 RIK).

OBJECTIVE: The purpose of this research is to make analysis, revision and estimation both reliability and accuracy of all measurements of radioiodine in the thyroid for residents of Ukraine, which were performed in 1986, and to justify the calibration factors to be applied for interpretation of measurements performed by non-calibrated devices. MATERIALS AND METHODS: The radioiodine activity in the thyroid for residents of the most contaminated oblasts of Ukraine has been calculated on the base of 150 thousands direct measurements of the content of 131I in thyroid obtained in the frames of the thyroid monitoring in 1986. A method for the calculation of measurement errors has been developed and the accuracy of the errors has been determined assuming that the density of errors' distribution for main parameters of the measurements is close to Gaussian. Using the results of laboratory measurements, the calibration factors have been determined for integrated radiometers SRP-68-01 - devices which were often used to perform the thyroid dosimetric monitoring. RESULTS: The distribution of estimates on the content of radioiodine in thyroid is close to the lognormal one with geometric mean being equal to 4.8 kBq and geometric standard deviation being equal to 3.8. Most of these estimates (90 %) are in the range of 0.58-47 kBq, and the main set of their relative errors (90 %) are between 0.1 and 0.6. Thus, the model of thyroid activity observation with classical additive error has been obtained.

Individualized internal exposure doses reconstruction for the persons of Ukraine State Register: Report 2. Locally-specific models and doses of persons living in Kozelets and Ripky raions of Chernihiv oblast. / Rekonstrukciya individualizirovannyx doz vnutrennego oblucheniya sub""ektov Gosudarstvennogo Registra Ukrainy: Soobshhenie 2. Lokal''no-specificheskie modeli i dozy oblucheniya zhitelej Kozeleckogo i Repkinskogo rajonov Chernigovskoj oblasti.

Study objective. Development a system of models and procedures for the individualized internal exposure doses reconstruction for the subjects of Ukrainian State Register of persons, affected due to the Chornobyl accident (SRU) and residing in radioactive contaminated territories of Kozelets and Ripky raions of Chernihiv oblast. Materials and methods. A description the schematic diagram and mathematical equations of ecological-dosimetric models are given that allow to reconstruct the individualized exposure doses from consumption of food contaminated with radiocesium of Chornobyl origin for inhabitants of two raions of Chernihiv oblast. Parameterization of the reconstruction models is based on the mathematical analysis of results for radioecological (radiocesium milk contamination) and dosimetric (radiocesium human body burden) monitorings, that were calculated in the period of 1986-2012 in the settlements of raions under consideration. Due to quite low level of radioactive cesium depositions on the ground in 1986, the territory of these raions was divided into two "territorial zones": TZ-1, an area where the 137Cs ground depositions density in 1986 exceeds 37 kBq/m2, and TZ-2, an area where this rate does not exceeds 37 kBq/m2. For each territorial zone in each raion, the initial time moment (year) was introduced in the reconstruction model. Since this year the concept of the so-called "reference dose" has been using. Its value was assigned to all persons, regardless of the results and availability of monitoring. The results of radioecological and dosimetric monitorings were used for setting in raion specific functions: the annual average concentration of 137Cs in milk per unit of 137Cs ground depositions for Kozelets raion, function of the temporary dynamic of 137Cs concentration in milk for Ripky raion, absolute raion milk equivalent of the diet (ARMEr), and relative age dependent intake of radiocesium with the diet. Results and conclusions. Models for individualized internal exposure doses reconstruction were applied to 27811 SRU subjects from Kozelets raion and 14553 SRU subjects from Ripky raion. Results of doses individualization are given as annual average values of internal and summarized (internal and external) exposure doses for the period of 1987-2012, as well as the distribution of SRU subjects of different raions according to the intervals of accumulat-ed doses over the entire period of observation.

Individualized internal exposure doses reconstruction for the persons of Ukraine State Register: Report 1. Locally-specific models and doses of persons living in Rokytne raion of Rivne oblast, Ovruch raion of Zhytomyr oblast and Ivankiv raion of Kyiv oblast. / Rekonstrukcija individualizirovannyh doz vnutrennego obluchenija subektov Gosudarstvennogo Registra Ukrainy: Soobshhenie 1. Lokal''no-specificheskie modeli i dozy obluchenija zhitelej Rokitnovskogo rajona Rovenskoj oblasti, Ovruchskogo rajona Zhitomirskoj oblasti i Ivankovskogo rajona Kievskoj oblasti.

Study objective. Dosimetric support of the Ukrainian State Register of persons, affected due to the Chornobyl accident (SRU). Development the system of models and procedures for the individualized internal doses reconstruction for the subjects of SRU residing in radioactive contaminated territories of Rokytne raion of Rivne oblast, Ovruch raion of Zhytomyr oblast and Ivankiv raion of Kyiv oblast. Materials and methods. A detailed description for the schematic diagram of the methodology and mathematical relations of ecological-dosimetric models are given. It allows to reconstruct the individualized doses from the ingestion of food contaminated by radiocesium after the Chornobyl accident for the subjects of SRU from three raions of Rivne, Zhytomyr and Kyiv oblasts. Phenomenologically, the developed models are close to the previously developed complex of ecological and dosimetric models intended to estimate the reference doses for the entire population of Ukraine. Calibration of model parameters is based on mathematical treatment for results of extensive radioecological (radiocesium milk contamination) and dosimetric (radiocesium burden in human body) monitorings, that were provided in the period of 1986-2012 in the settlements of raions under consideration. Completeness and periodicity of radioecological and dosimetric monitorings allowed to realize the settlement-specific approach for dose reconstruction, wherein for each settlement either the function of radiocesium intake with diet or the function of time-variation of radiocesium concentration in the local cow's milk were established. Absolute raion milk equivalent of the diet (ARMEr) and relative age dependent intake of radiocesium with diet are specified as a raion-specific functions for each raion. ARMEr is used to calculate the doses of adults in the settlement for which the function was specified. RRI is used to calculate the doses for the subjects of four children age groups (< 2 years old, 3-7 years old, 8-12 years old, 13-17 years old). Results and conclusions. Models for individualized internal exposure doses reconstruction of SRU subjects are developed. The individualized doses are estimated for 28711 SRU subjects from Rokytne raion, 18790 SRU subjects from Ivankiv raion and 41585 SRU subjects from Ovruch raion. Results of doses individualization are given as annual average doses for the period of 1987-2012. The distribution of SRU subjects of different raions over the intervals of doses accumulated over the entire observation period is also given. Values of total (from internal and external exposure) doses for SRU subjects of the raions under consideration are given, as well.