Modern radioecological situation at the site of the peaceful underground nuclear explosion "Crystal" and radionuclides in the surface waters of the adjacent territory (western Yakutia)

The radioecological situation at the site of the peaceful underground nuclear explosion «Crystal» after removal land cover and installation of the arti cial cover of rock from nearby quarry above the epicenter is considered. In 2012 the ambient dose equivalent rate of gamma radiation varied from 0.04 to 0.066 μSv/h, in 2019 the content of radionuclides in soils was (Bq/kg): ⁹⁰Sr 2.5-5.3, ^239,240Pu 0.03-25.4, ¹³⁷Cs <2.0. In 2018-2020 the activity of radionuclides in surface water was (Bq/dm³): in runo from under the arti cial cover ³H 4-12, ⁹⁰Sr 0.004-0.4, ^239,240Pu <10^-6, in local river water ³H 4-10.2, ⁹⁰Sr 0.004-0.3. At present, the impact of surface runo from the «Crystal» site on the river network is assessed as insigni cant. No more than 1/3 of ³H in the local river water comes with precipitation, and the rest of ³H comes from the «Crystal» explosion zone, mainly by an underground route. At least 91-96% of ⁹⁰Sr in the local river water is due to the «Crystal» explosion: part of it comes from the explosion zone by an underground route, part is washed o from the surface of landscapes.

surface waters, underground brines, underground nuclear explosion, special radioactive waste, geological environment, radionuclides, tritium, radiostrontium, yakutia