Modeling of ⁶⁰Co migration in the aquifer

¹ Burnasyan Federal Medical Biophysical Centre Federal Medical Biological agency, 123182, Zhivopisnaya 46 Moscow, Russia
² All-Russian Scientific Research Institute for Nuclear Power Plant Operation, 109507, Ferganskaya 25, Moscow, Russia
³ Novovoronezh NPP, 396072 Novovoronezh, Voronezh Region, Russia

Abstract

In 1985, at Novovoronezh NPP (NVNPP), liquid radioactive waste leaked from the storage facility No2 (SLW-2). The leakage took place along the perimeter of the storage facility from the underpan closed with soil; therefore the leakage has been discovered in about half year, during water sampling from the test boreholes. According to the assessments, a volume of liquid waste released in soil was about 480 m³ with ∼76 and 15 TBq activities of ⁶⁰Co and ¹³⁷Cs, respectively. Up to now, the majority of ¹³⁷Cs amount has been localized at the place of the leakage – in the unsaturated zone at the level of the underpan; ⁶⁰Co was infiltrated into the aquifer and spread through – ground waters at about 700 meters up to Don River. ⁶⁰Co occurrence in the river was registered in 1995. The ground water discharge into Don River caused contamination of some part of bottom sediments up to the level of solid radioactive waste. This paper presents the calculation results of ⁶⁰Co migration via ground waters.