Assessment of Potential Radiation Hazard of the Former Uranium Facilities for the Population of the Istiklol City of the Republic of Tadzhikistan

Abstract

The article presents the results of alpha, gamma spectrometric analyzes of samples, dosimetry, radon monitoring of the estimated areas in the Istiklol city. It has been established that the specific activity of radionuclides for uranium and radium in the tailing materials are in the range: 1405 – 2140, 5935 – 9843 Bq / kg, respectively. Based on the results of the monitoring of gamma radiation and radon volume activity at Istiklol city sites, it has been established that gamma radiation ambient equivalent dose rate varies from 0.52 to 1.78 μSv / h, and radon volume activity in air ranges from 20 and 45 Bq / m3. It is shown that the radon concentration in the air above the surface of tailings is not high. However, the exhalation of radon from the soil surface of all the tailings dumps examined is above the standard (1 Bq / (m2·s). The results of measurements of radon volume activity in the air of residential buildings and facilities located on the territory of Istiklol city have shown that the value of radon volume activity is within the limits of 44 – 195 Bq / m3. A high value of radon volume activity is noted in the former dilapidated plant (1319 Bq / m3). Gamma and alpha spectrometric studies revealed that the average values of the activity concentration of uranium and radium in the soils for tailings and the pit are for 234U – 65365 Bq / kg, for 238U – 50295 Bq / kg, and for 226Ra – 3800 Bq / kg. To estimate the doses of population irradiation via the water pathway were taken the average values of the volumetric activity of 234U, 238U, 226Ra in the waters. Maximum values of volumetric activity of radionuclides were observed in samples of drainage water, Bq / m3: 234U – 530000, 238U – 390000, 226Ra – 185. To calculate the contributions of various radiation factors to an additional annual dose of irradiation, the population was divided into four hypothetical groups. The time duration of stay of various hypothetical population groups in the areas of potential irradiation, radiation dose due to water use from contaminated water sources and additional factors in Istiklol were taken into account.The main contributor to the additional radiation dose received by hypothetical population groups is external irradiation during the stay on the territory of the FBR and tailing dumps, and internal irradiation due to the use of contaminated water.

Radon monitoring on the territory of Northern Tajikistan

“…Результаты радиационного мониторинга на территории Дигмайского хвостохранилища показали, что средняя мощность амбиентной дозы на поверхности хвостохранилища достигает 20 мкЗв/ч, а ППР с поверхности хвостового материала достигает 65 000 мБк/(м 2 •с), при этом ОА радона в атмосферном воздухе над хвостохранилищем на разных участках варьирует от 200 до 1000 Бк/м 3 . Также установлено, что удельная активность 238 U в хвостовом материале достигает 980 Бк/кг, а 226 Ra -7620 Бк/кг [3].…”

Assessment of the potential radiation hazard of the Dehmoy tailings pond (Tajikistan) for the population living around it

“…Мгновенные измерения ОА радона проводились с помощью радиометра радона РРА-01М-03. При помощи пробоотборного устройства ПОУ-04 была измерена плотность потока радона (ППР) с поверхности хвостохранилища Дигмай [2]. По результатам замеров ППР на площадках, равномерно распределенных по поверхности хвостохранилища, произведена оценка годового выброса радона.…”

210Po and 210Pb Isotopes Content in the Water of Artificial Lake of Istiklol City of the Republic of Tajikistan and their Bioaccumulation in the Fish

“…Ранее в работах [1,2] были даны оценки потенциальной радиационной опасности бывших урановых объектов Республики Таджикистан, в том числе и г. Истиклола. Как известно, добыча урана является наиболее опасным производством.…”