Comprehensive radioecological monitoring of terrestrial ecosystems in the vicinity of the Rooppur nuclear power plant (People’s Republic of Bangladesh)

Abstract

Terrestrial ecosystems (soil and plants) accumulate artificial radionuclides from emissions of nuclear power plants. In order to control the radiation situation in the vicinity of the Rooppur Nuclear Power Plant (Bangladesh), a system of radioecological monitoring of terrestrial (mainly agricultural) ecosystems has been created. Radioecological studies were carried out in 2014–2017 before the start of operation of the Rooppur Nuclear Power Plant. Assessment of specific activity in soil of natural (40K − 750–855, 226Ra − 44–52, 232Th − 63–75 Bq.kg−1) and artificial (90Sr − 0.5–1.6, 137Cs − 1.2–2.5 Bq.kg−1) radionuclides before the start of operation the Rooppur Nuclear Power Plant has revealed the radioisotope content in the soil being consistent with other areas in Bangladesh. The 137Cs/90Sr ratio in the soil is 1.5–2.8, which is close to the level of global radioactive fallout. Ambient dose equivalent rates in the 30-km zone of influence of the nuclear power plant vary within 0.11–0.15 μSv.h−1 and are determined by the natural background radiation. Agricultural crops of arable land, pastures and orchards accumulate 1.5–2 times more 90Sr compared to 137Cs. The accumulation coefficients of radionuclides by plants are determined by the crops species and soil characteristics. The monitoring system will make it possible to assess long-term changes in the radioecological situation in the zone of influence of the Rooppur Nuclear Power Plant after the start of its operation.