Study of the Power Beam Pattern of RATAN-600 During the Deep RZF Survey (1998-2003)

This paper proposes a method for constructing an experimental power beam pattern (PB) of RATAN-600 based on the sample of NVSS sources observed in the process of a deep sky survey near local zenith. The data obtained from observations of radio sources at wave 7.6 cm in nine bands of the survey (the 2002 and 2003 sets) are used to construct vertical PB of the telescope at rather large offsets from the central horizontal section of the PB (+/-36'). The experimental PBs obtained using different methods are compared and the root-mean-square deviations of the experimental PB from the corresponding computed PB are determined. The stability of the power beam pattern in its central part (+/-6') during the RATAN-600 Zenith Field (RZF) survey (1998-2003) and the accuracies of the fluxes of the sources observed within the framework of this survey and included into the RZF catalog are estimated.Comment: 15 pages, 17 figure

Радиационно-гигиеническая оценка содержания и распределения 90Sr и 137Cs в ихтиофауне Обь-Иртышской речной системы

The aim of the work is the radiation-hygienic assessment of 90Sr and  137Cs content in fish of the Ob-Irtysh river system and the study of the basic laws of the radionuclides accumulation in the ichthyofauna of these rivers. To perform this task, long-term results of radioecological studies of fish from the Techa, Irtysh and Ob rivers for the period 2004-2016 were used. Fish as a food product was evaluated according to two criteria: a) permissible levels of radionuclides specific activity (SanPiN 2.3.2.1078-01); b) using the indicator of conformity В and uncertainty of its definition ΔВ (GOST 32161-2013 and GOST 32163-2013). It is shown that a higher content of radionuclides is observed in the ichthyofauna of the Techa river (1379.1 Bq/kg for 90Sr and 41.9 Bq/kg for 137Cs). On the Ob and Irtysh rivers, the average specific activity of radionuclides in fish was significantly lower and slightly changed during the surveyed area: for 90Sr in the range of 6.0 ÷ 8.1 Bq/kg (mean 6.8), for 137Cs – 0.6 ÷ 1.9 Bq/kg (mean 1.3). Assessment for compliance with radiation safety criteria using the indicator of compliance and its uncertainty (В+ΔВ) confirmed the unsuitability of use for food purposes by the radiation factor of all studied fish species from the Techa river (45÷55 >1). Fish from all other studied areas of the Ob-Irtysh river system can be used for food without restrictions (0,06÷0,53 < 1). The distribution of 90Sr and 137Cs in the ichthyofauna of the Ob-Irtysh river system part over a 2400 km is presented in the form of empirical regression models. The models describe a sharp decrease in the radionuclides specific activity in fish in the Techa and Iset rivers by two orders for 90Sr (from 2000 to 20 Bq/kg), and by one order for 137Cs (from 40 to 2 Bq/kg). With a high degree of reliability (R2>0.86 for 90Sr and R2>0.92 for 137Cs), the presence of power relationships between the content of radionuclides in the ichthyofauna and their content in water was shown, with adequacy confirmed by Fisher’s F-criteria. This can be used for a preliminary assessment of the radionuclides level in fish based on the results of measurements of the average annual concentrations of these radionuclides in water.Целью настоящей работы является радиационно-гигиеническая оценка содержания 90Sr и 137Cs в рыбе Обь-Иртышской речной системы и изучение основных закономерностей накопления радионуклидов в ихтиофауне этих рек. Для выполнения данной задачи были использованы многолетние результаты радиоэкологических исследований рыбы из рек Теча, Иртыш и Обь за период 2004–2016 гг. Выполнена оценка рыбы как пищевого продукта по двум критериям: а) допустимые уровни удельной активности радионуклидов (СанПиН 2.3.2.1078-01); б) с использованием показателя соответствия В и неопределенности его определения ΔВ (ГОСТ 32161-2013 и ГОСТ 32163-2013). Показано, что более высокое содержание радионуклидов наблюдается в ихтиофауне реки Теча (1379,1 Бк/кг по 90Sr и 41,9 Бк/кг по 137Cs). На реках Обь и Иртыш средние показатели удельной активности радионуклидов в рыбе были существенно ниже и слабо изменялись на протяжении обследованного участка: для 90Sr в диапазоне 6,0–8,1 Бк/кг (среднее 6,8), для 137Cs – 0,6–1,9 Бк/кг (среднее 1,3). Оценка на соответствие критериям радиационной безопасности с использованием показателя соответствия В и его неопределенности ΔВ (В+ΔВ) подтвердила непригодность использования в пищевых целях по радиационному фактору всех исследованных видов рыб из р. Течи (45–55 >1). Рыба из всех остальных исследованных участков Обь-Иртышской речной системы может быть использована в пищу без ограничений (0,06–0,53 < 1). Закономерности распределения 90Sr и 137Cs в ихтиофауне Обь-Иртышской речной системы на участке протяженностью 2400 км представлены в виде эмпирических регрессионных моделей. Модели описывают резкое снижение удельной активности радионуклидов в рыбе на участке рек Теча – Исеть на два порядка величин по 90Sr (с 2000 до 20 Бк/кг) и на один порядок по 137Cs (с 40 до 2 Бк/кг). С высокой степенью достоверности (R2 >0,86 для 90Sr и R2 >0,92 для 137Cs) показано наличие степенных зависимостей между содержанием радионуклидов в ихтиофауне и их содержанием в воде, с адекватностью, подтвержденной критериями Фишера. Это может быть использовано для предварительной оценки уровня содержания радионуклидов в рыбе на основе результатов измерений среднегодовых концентраций этих радионуклидов в воде

Оценка влияния эксплуатации реактора БН-800 на содержание радионуклидов в местных продуктах питания района Белоярской АЭС

The research results are presented as an analysis of long-term data on the effect of gas-aerosol emissions and liquid discharges of Beloyarsk NPP and the Institute of Reactor Materials on the content of artificial radionuclides in local foodstuffs. It was noted that the distance and directions from radiation-hazardous facilities do not significantly affect the accumulation of 90Sr and 137Cs in potatoes and milk. The investigation of a wide range of foodstuffs from the private households of 23 settlements, forests, rivers, and a reservoir of the 30-km zone of the Beloyarsk NPP influence showed that the operation of the BN-800 reactor since 2016 did not lead to a registered increase in the content of artificial radionuclides in agricultural and natural foodstuffs. The maximum specific activities of 90Sr (0.84 Bq/kg) and 137Cs (0.26 Bq/kg) in root vegetables, potatoes, melons and vegetables were noted before the start of operation of the new power unit and were 45 and 300 times, respectively, lower than the current SanPiN standards. The highest content of 90Sr in milk (0.41 Bq/l) was 60 times lower than the requirements of SanPiN, 137Cs (0.11 Bq/l) was 900 times less than the permissible levels. In poultry, the specific activity of 90Sr (0.2-0.3 Bq/kg) and 137Cs (0.13-0.16 Bq/kg) has remained stable low in recent years, and the standardised content of 137Cs in beef (maximum 0.12 Bq/kg) more than 1.5 thousand times lower than the requirements of SanPiN. The highest concentration of 137Cs in wild berries, found in strawberries (1.27 Bq/kg), was 125 times less than SanPiN standards. The content of 90Sr in mushrooms was at the level of 0.1-2.5 Bq/kg, the content of 137Cs is slightly higher than - 0.6-5.8 Bq/kg. The maximum recorded specific activity of 137Cs in mushrooms was more than 80 times lower than the requirements of SanPiN. During the observation period, a decrease of up to 20% or more in the content of artificial radionuclides in samples of 5 fish species was noted; the maximum levels of 90Sr and 137Cs in it were 14 times lower than the strictest SanPiN standards (using fish for baby food). Selective radiation monitoring of foodstuffs of Beloyarsk NPP area aimed at 3H and 14C showed that the content of these radionuclides in foodstuffs was low, close to the background level. In agricultural products, 3H and 14C accumulated to a greater extent in potatoes and milk, and in natural products – in rough boletus and bream. There was noted a need to continue research on the accumulation of 3H and 14C in foodstuffs of Beloyarsk NPP vicinity.В работе представлен анализ многолетних данных по влиянию газоаэрозольных выбросов и жидких сбросов Белоярской АЭС и Института реакторных материалов на содержание техногенных радионуклидов в местных пищевых продуктах. Отмечено, что расстояние и направления от радиационно опасных объектов значимо не влияют на накопление 90Sr и 137Cs в картофеле и молоке. На примере широкого ряда продуктов питания из частного сектора 23 населенных пунктов, лесов, рек и водохранилища 30-километрвой зоны влияния Белоярской АЭС показано, что эксплуатация с 2016 г. реактора БН-800 не привела к регистрируемому увеличению содержания техногенных радионуклидов в сельскохозяйственной и природной пищевой продукции. Максимальные удельные активности 90Sr (0,84 Бк/кг) и 137Cs (0,26 Бк/кг) в корнеплодах, картофеле, бахчевых и овощах отмечались до начала эксплуатации нового энергоблока и были в 45 и 300 раз соответственно ниже действующих нормативов СанПиН. Наиболее высокое содержание в молоке 90Sr (0,41 Бк/л) было в 60 раз ниже требований СанПиН, 137Cs (0,11 Бк/л) в 900 раз меньше нормативов. В мясе домашней птицы удельная активность 90Sr (0,2–0,3 Бк/кг) и 137Cs (0,13–0,16 Бк/кг) в последние годы остается стабильно низкой, а нормируемое содержание 137Cs в говядине (максимально – 0,12 Бк/кг) более чем в 1,5 тыс. раз ниже требований СанПиН. Наиболее высокая концентрация 137Cs в лесных ягодах, обнаруженная в землянике (1,27 Бк/кг), меньше нормативов СанПиН в 125 раз. Содержание 90Sr в грибах находится на уровне 0,1–2,5 Бк/кг, 137Cs несколько выше – 0,6–5,8 Бк/кг. Максимально зафиксированная удельная активность 137Cs в грибах ниже требований СанПиН более чем в 80 раз. Отмечено уменьшение за период наблюдений до 20% и более содержания техногенных радионуклидов в пробах 5 видов рыб; максимальные уровни 90Sr и 137Cs в ней были ниже наиболее жестких нормативов СанПиН (использование рыбы для детского питания) в 14 раз. Выборочный радиационный контроль пищевых продуктов района Белоярской АЭС на 3H и 14C показал, что содержание этих радионуклидов в продуктах питания находится на низком, близком к фоновому уровне. В сельскохозяйственной продукции 3H и 14C в большей степени накапливаются в картофеле и молоке, из при- родных продуктов в подберезовике и леще. Отмечена необходимость продолжения исследований по изучению накопления 3H и 14C в продуктах питания района Белоярской АЭС

Radiation-hygienic assessment of the concentration and distribution of ⁹⁰Sr and ¹³⁷Cs in ichthyofauna of the Ob’-Irtysh river system

The aim of the work is the radiation-hygienic assessment of 90Sr and  137Cs content in fish of the Ob-Irtysh river system and the study of the basic laws of the radionuclides accumulation in the ichthyofauna of these rivers. To perform this task, long-term results of radioecological studies of fish from the Techa, Irtysh and Ob rivers for the period 2004-2016 were used. Fish as a food product was evaluated according to two criteria: a) permissible levels of radionuclides specific activity (SanPiN 2.3.2.1078-01); b) using the indicator of conformity В and uncertainty of its definition ΔВ (GOST 32161-2013 and GOST 32163-2013). It is shown that a higher content of radionuclides is observed in the ichthyofauna of the Techa river (1379.1 Bq/kg for 90Sr and 41.9 Bq/kg for 137Cs). On the Ob and Irtysh rivers, the average specific activity of radionuclides in fish was significantly lower and slightly changed during the surveyed area: for 90Sr in the range of 6.0 ÷ 8.1 Bq/kg (mean 6.8), for 137Cs – 0.6 ÷ 1.9 Bq/kg (mean 1.3). Assessment for compliance with radiation safety criteria using the indicator of compliance and its uncertainty (В+ΔВ) confirmed the unsuitability of use for food purposes by the radiation factor of all studied fish species from the Techa river (45÷55 >1). Fish from all other studied areas of the Ob-Irtysh river system can be used for food without restrictions (0,06÷0,53 < 1). The distribution of 90Sr and 137Cs in the ichthyofauna of the Ob-Irtysh river system part over a 2400 km is presented in the form of empirical regression models. The models describe a sharp decrease in the radionuclides specific activity in fish in the Techa and Iset rivers by two orders for 90Sr (from 2000 to 20 Bq/kg), and by one order for 137Cs (from 40 to 2 Bq/kg). With a high degree of reliability (R2>0.86 for 90Sr and R2>0.92 for 137Cs), the presence of power relationships between the content of radionuclides in the ichthyofauna and their content in water was shown, with adequacy confirmed by Fisher’s F-criteria. This can be used for a preliminary assessment of the radionuclides level in fish based on the results of measurements of the average annual concentrations of these radionuclides in water

Assessment of the impact of the BN-800 reactor operation on the radionuclides content in local foodstuffs in the vicinity of Beloyarsk NPP

The research results are presented as an analysis of long-term data on the effect of gas-aerosol emissions and liquid discharges of Beloyarsk NPP and the Institute of Reactor Materials on the content of artificial radionuclides in local foodstuffs. It was noted that the distance and directions from radiation-hazardous facilities do not significantly affect the accumulation of 90Sr and 137Cs in potatoes and milk. The investigation of a wide range of foodstuffs from the private households of 23 settlements, forests, rivers, and a reservoir of the 30-km zone of the Beloyarsk NPP influence showed that the operation of the BN-800 reactor since 2016 did not lead to a registered increase in the content of artificial radionuclides in agricultural and natural foodstuffs. The maximum specific activities of 90Sr (0.84 Bq/kg) and 137Cs (0.26 Bq/kg) in root vegetables, potatoes, melons and vegetables were noted before the start of operation of the new power unit and were 45 and 300 times, respectively, lower than the current SanPiN standards. The highest content of 90Sr in milk (0.41 Bq/l) was 60 times lower than the requirements of SanPiN, 137Cs (0.11 Bq/l) was 900 times less than the permissible levels. In poultry, the specific activity of 90Sr (0.2-0.3 Bq/kg) and 137Cs (0.13-0.16 Bq/kg) has remained stable low in recent years, and the standardised content of 137Cs in beef (maximum 0.12 Bq/kg) more than 1.5 thousand times lower than the requirements of SanPiN. The highest concentration of 137Cs in wild berries, found in strawberries (1.27 Bq/kg), was 125 times less than SanPiN standards. The content of 90Sr in mushrooms was at the level of 0.1-2.5 Bq/kg, the content of 137Cs is slightly higher than - 0.6-5.8 Bq/kg. The maximum recorded specific activity of 137Cs in mushrooms was more than 80 times lower than the requirements of SanPiN. During the observation period, a decrease of up to 20% or more in the content of artificial radionuclides in samples of 5 fish species was noted; the maximum levels of 90Sr and 137Cs in it were 14 times lower than the strictest SanPiN standards (using fish for baby food). Selective radiation monitoring of foodstuffs of Beloyarsk NPP area aimed at 3H and 14C showed that the content of these radionuclides in foodstuffs was low, close to the background level. In agricultural products, 3H and 14C accumulated to a greater extent in potatoes and milk, and in natural products – in rough boletus and bream. There was noted a need to continue research on the accumulation of 3H and 14C in foodstuffs of Beloyarsk NPP vicinity