The results of the analysis of the 137Cs aggregated transfer factors (Tag) change in fodder of agricultural animals (hay, haylage, silage, and green fodder) in the southwestern districts of Bryansk region over the 35 years since the Chernobyl accident are presented. It is shown that the rates of Tag reduction across districts and zones of radioactive contamination varied significantly, while the dynamics of their change had an uneven character. Four time intervals are distinguished for the assessments; specifically, from 1987 to 1992, from 1993 to 2006, from 2007 to 2015, and from 2016 to 2021. The first period covered the time after the accident, when the countermeasures were carried out on a maximum scale; the second one, when the scales of remediation decreased significantly; the third period was a time (from 2006 to 2016) when the dynamics of the Tag reduction was influenced by the Federal Target Program (FTP) “Preservation and Restoration of Soil Fertility of Agricultural Lands and Agricultural Landscapes as a National Asset of Russia for 2006–2013”; and the fourth one, from 2016 to 2021, in the remote period after the accident, when the volumes of rehabilitation of agricultural lands were very low. The half-lives calculated for the period of intensive countermeasure implementation ranged from 0.73 to two years. During the next period, the 137Cs decrease in all types of forage crops strongly slowed down, and in many areas, there was a tendency toward an increase in the Tag values. During the third and fourth periods, the dynamics was of multidirectional character; namely, in the districts where the FTP activities were applied on a full scale, an essential increase in the 137Cs Tag values to fodder plants was noted; whereas a further increase in this parameter was observed in the districts with limited application of the countermeasures. The efficiency of remediation was estimated by the criterion of reduction of Tag values (reduction factor) in zones with different 137Cs deposition density on agricultural lands. It was also noted that the reduction factor across different time intervals after the accident ranged from 1.1 (silage) to 5.1 (haylage). The highest efficiency in fodder crops Tag reduction was observed both in the first period after the accident (1986–1992) and in the period of the FTP implementation. It was shown that the Tag values in the zone with a deposition density from 185 to 555 kBq/m2 did not differ significantly from those in the zone with a deposition density of 555–1480 kBq/m2.

The paper continues the cycle of publications addressed to the study of regularities of 137Cs content changes in agricultural products after the Chernobyl accident. The aim of the studies was to analyze the information describing changes in the 137Cs concentrations in agricultural animal forage: hay, haylage, silage and green fodder in the southwestern districts of the Bryansk region affected by the contamination after the ChNPP accident. The data on countermeasures in the fodder production are given and the system of radiological monitoring of fodder contamination is described. It is shown that the dynamics of changes in the 137Cs concentrations in fodder was mainly determined by the dynamics of implementation of remedial measures. The effective halflives of 137Cs concentration in forages during the first period after the accident (1987-1990) varied from 0.57 to 2.7 years. Subsequently (1991-2021) the decrease in feed contamination slowed down and the half-lives ranged from 8.0 to 50.0 years and longer depending on the scope of remediation and the characteristics of the plants used for the animal feed production.

A wide range of countermeasures and remedial actions has been developed and used to mitigate the consequences of the Chernobyl accident. This article summarizes the basic information on the application of countermeasures in agriculture over the 35 years after the accident and provides data on their effectiveness. The experience of using agricultural remedial measures and their influence on the radiological situation in different periods after the accident are analyzed. The most important aspects are highlighted, and the necessity of using the aftermath experience for improving emergency response systems in agriculture for potential emergencies is demonstrated.

The main techniques of animal product sampling used in different time periods after the Chernobyl accident are summarised and lessons learned from this analysis are presented. It was shown that simple instruments for measurement γ-radiation in the environment can also be effectively implemented for measurement of γ-emitters in animal products even though these were not originally developed to measure radioactivity in food. The lessons learned related to the major tasks of the monitoring such "what to sample", "where to sample" and "when to sample". The role and example of application of supplementary data on radionuclide of concern properties for sampling planning are also discussed. Based on the statistical analysis of the data obtained in the affected settlement it was shown that radionuclide concentration in the animal products can be fitted by the log-normal distributions whilst the dispersion of the logarithms of the activity 137Cs concentrations in milk is not dependent on the local settlement specific factors. Based on these findings the novel approach for justification of the number of samples that should to be taken to obtain the GM estimate with predefined precision for given variability of the data is suggested.

Представлена история ФГБНУ ВНИИРАЭ. Показаны основные направления научных исследований и итоги 50-летней деятельности. The history of RIRAE is presented. The main directions of scientific research and the results of 50 years of activity are shown.

Описаны хронология и исторические аспекты участия сотрудников ВНИИРАЭ в ликвидации последствий аварии на Чернобыльской АЭС. Представлен масштаб радиоактивного загрязнения пострадавших от аварии на ЧАЭС территорий и уровень радиологических проблем в сельском хозяйстве. Дана краткая характеристика разработанной во ВНИИРАЭ системы ведения агропромышленного производства в различных зонах радиоактивного загрязнения и периодов после аварии, включающей: радиационный мониторинг и контроль продукции сельского хозяйства, технологии возделывания сельскохозяйственных культур, специальные препараты и сорбенты, снижающие накопление радионуклидов в продукции животноводства, а также способы технологической переработки сельскохозяйственного сырья и продукции. Показано, что широкомасштабное внедрение защитных и реабилитационных мероприятий в сельском хозяйстве на радиоактивно загрязненных территориях в значительной степени способствовало нормализации радиационной обстановки, снижению дозовых нагрузок населения и улучшению социально-экономической ситуации в регионе аварии на ЧАЭС. The chronology and historical aspects of RIRAE stuff participation in the elimination of Chernobyl NPP accident consequences are described. The scale of radioactive contamination of the territories affected by the Chernobyl NPP accident and the level of radiological problems in agriculture are presented. A brief description is given of a system developed by RIRAE for agricultural production in various zones of radioactive contamination and periods after the accident, including: radiation monitoring and control of agricultural products, crop cultivation technologies, special preparations and sorbents that reduce the accumulation of radionuclides in livestock products, as well as methods technological processing of agricultural raw materials and products. It has been shown that the large-scale implementation of protective and rehabilitation measures in agriculture in radioactively contaminated territories has significantly contributed to the normalization of the radiation situation, reduction of exposures doses to the population and improvement of the socio-economic situation in the region of the Chernobyl accident.

В 2020 году исполняется 50 лет Всероссийскому научно-­исследовательскому институту радиологии и агроэкологии (ранее – Всесоюзный научно-­исследовательский институт сельскохозяйственной радиологии). Образованный в период холодной вой­ны институт в первую очередь был призван решать проблемы устойчивости сельского хозяйства в условиях возможного ядерного конфликта. Параллельно проходили исследования по «мирной» тематике, включая координацию работы 50 институтов-­соисполнителей системы МСХ СССР, министерств сельского хозяйства союзных республик и ВАСХНИЛ по вопросам применения достижений атомной науки и техники в сельском хозяйстве. Разработки института нашли применение при совершенствовании военной доктрины СССР, а сотрудники были удостоены Государственных премий СССР. Об истории института, достижениях, направлениях работы и перспективах развития рассказали директор ФГБНУ ВНИИРАЭ, член-корреспондент РАН, лауреат Государственной премии РФ Наталья Ивановна Санжарова и руководители подразделений.

The aim of this study was to analyze the current radioecological situation in agriculture in five south-west districts of the Bryansk region, which were exposed to the most radiation influence due to the accident at the Chernobyl NPP. Currently, there are 135 collective farms in the observed areas. The total area of agricultural lands was 266.2 thousand hectares. The area of agricultural lands with 137Cs contamination over 37 kBq/m2 was 244.8 thousand hectares in 2018. The area of arable land, hay fields and pastures located in the zone with a 137Cs soil surface activity in a range of 37–185 kBq/m2 is 135.1 thousand hectares, 185–555 kBq/m2– 88.3 thousand hectares, 555-1480 kBq/m2 – 19.8 thousand hectares. At present, only 21.4 thousand hectares (8% of the agricultural lands in the considered areas) don’t exceed contamination levels of 137Cs 37 kBq/m2, and they can be classified as “clean territory”. Analysis of the agricultural products radiation monitoring data from the collective farms of the south-west districts of the Bryansk region showed that the part of feed and crop products exceeded the standards varied from 4 to 15% in 2017-2018. The high content of 137Сs in the feed of several collective farms determined the excess of sanitary and hygienic standards in livestock products from these farms – milk in 4-8% of total samples, beef in 5–8% of total samples. The collective farms located in Krasnogorsky and Novozybkovsky districts of the Bryansk region, with a high risk of exceeding the standards for the content of radionuclides in the agricultural products, was identified. The required volumes of rehabilitation measures in the plant growing and animal husbandry of the south-west districts of the Bryansk region was indicated. It was found that 75 thousand hectares of the total area of agricultural lands need radical improvement and the introduction of higher doses of agromeliorants to produce plant-growing and fodder products corresponding to the legislation standards. To produce milk and beef that comply with sanitary and hygienic standards for livestock products, it is necessary to use ferrocyanide treatment in volumes of 10.5 t/a. It was shown that most radioactively contaminated rural areas need individual programs for the application of rehabilitation technologies. Such programs should provide the population safety and domestic activity.

The aim of this study was to analyze the current radioecological situation in agriculture in five south-west districts of the Bryansk region, which were exposed to the most radiation influence due to the accident at the Chernobyl NPP. Currently, there are 135 collective farms in the observed areas. The total area of agricultural lands was 266.2 thousand hectares. The area of agricultural lands with 137Cs contamination over 37 kBq/m2 was 244.8 thousand hectares in 2018. The area of arable land, hay fields and pastures located in the zone with a 137Cs soil surface activity in a range of 37–185 kBq/m2 is 135.1 thousand hectares, 185–555 kBq/m2– 88.3 thousand hectares, 555-1480 kBq/m2 – 19.8 thousand hectares. At present, only 21.4 thousand hectares (8% of the agricultural lands in the considered areas) don’t exceed contamination levels of 137Cs 37 kBq/m2, and they can be classified as “clean territory”. Analysis of the agricultural products radiation monitoring data from the collective farms of the south-west districts of the Bryansk region showed that the part of feed and crop products exceeded the standards varied from 4 to 15% in 2017-2018. The high content of 137Сs in the feed of several collective farms determined the excess of sanitary and hygienic standards in livestock products from these farms – milk in 4-8% of total samples, beef in 5–8% of total samples. The collective farms located in Krasnogorsky and Novozybkovsky districts of the Bryansk region, with a high risk of exceeding the standards for the content of radionuclides in the agricultural products, was identified. The required volumes of rehabilitation measures in the plant growing and animal husbandry of the south-west districts of the Bryansk region was indicated. It was found that 75 thousand hectares of the total area of agricultural lands need radical improvement and the introduction of higher doses of agromeliorants to produce plant-growing and fodder products corresponding to the legislation standards. To produce milk and beef that comply with sanitary and hygienic standards for livestock products, it is necessary to use ferrocyanide treatment in volumes of 10.5 t/a. It was shown that most radioactively contaminated rural areas need individual programs for the application of rehabilitation technologies. Such programs should provide the population safety and domestic activity.

The main method of performing a cadastral valuation of lands contaminated with radionuclides due to the Chernobyl accident is based on accounting additional costs for remediation measures to obtain agricultural products that meet regulatory requirements. This technique was tested using the example of radioactively contaminated lands in the Gordeevsky and Zlynkovsky districts of the Bryansk oblast. This paper reports the changes in the cadastral value of lands, taking the contamination density into account.

Современное состояние и прогноз загрязнения 137 Cs сельскохозяйственных угодий Брянской, Калужской, Орловской и Тульской областей, подвергшихся воздействию аварии на Чернобыльской АЭС Панов А.В., Санжарова Н

В восстановительный период после аварии наибольшую актуальность приобретает проблема возвращения в хозяйственный оборот территорий с высокими уровнями радиоактивного загрязнения, ранее выведенных из землепользования после аварии на ЧАЭС. Для решения этой задачи разработана геоинформационная система (ГИС), в основе которой лежит информация о текущем состоянии отчужденных земель. Построены электронные карты, позволяющие выполнить оценку необходимости проведения реабилитационных мероприятий и наглядно продемонстрировать эффективность их применения на загрязненных территориях.

The paper describes the procedure of cadastral works of the identification of contaminated territories; the types and efficiency of measures of rehabilitation in order to reduce the contamination by 137Cs production to the appropriate level of sanitary and hygienic standards. On the example of the collective farms of the Krasnogorsk district of the Bryansk region (in which sandy, loamy, gley and peat soils dominate) affected by the Chernobyl accident, the assessment of cadastral estimation of agricultural lands contaminated with radionuclides is carried out. Cadastral estimation of arable lands, hayfields and pastures used for agricultural production is calculated. The cadastral value of agricultural land contaminated with radionuclides is calculated for arable land with crop zone rotation (grain, potatoes, annual grasses) and sections of hay-pasture use (perennial grasses). Studies are conducted both in local level (individual farms) and regional (the all area). It is shown, that cadastral estimation of agricultural land changes as follows: arable lands from 23 to 59 thousand rub/ha, hayfields and pastures from 75 to 86 thousand rub/ha in dependence on contamination levels of 137Cs and soil characteristics. The results of this research can be used by agriculture, cadastral engineer and investment-governmental companies operating in the field of agro-industrial complex on the contaminated areas.